Progress Energy (PREX) 10-Q 4 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2016shares
Document Information [Line Items]
Entity Registrant Name	Duke Energy Corporation
Entity Central Index Key	1,326,160
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding	688,933,508
Duke Energy Carolinas [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Carolinas, LLC
Entity Central Index Key	30,371
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Progress Energy [Member]
Document Information [Line Items]
Entity Registrant Name	Progress Energy, Inc
Entity Central Index Key	1,094,093
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Progress [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Progress, LLC
Entity Central Index Key	17,797
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Florida [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Florida, LLC
Entity Central Index Key	37,637
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Ohio [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Ohio, Inc.
Entity Central Index Key	20,290
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Indiana [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Indiana, LLC
Entity Central Index Key	81,020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating Revenues
Regulated electric	$ 4,965	$ 5,090	$ 10,018	$ 10,547
Nonregulated electric and other	422	403	822	780
Regulated natural gas	97	96	266	327
Total operating revenues	5,484	5,589	11,106	11,654
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,509	1,721	3,086	3,662
Fuel used in electric generation and purchased power – nonregulated	82	118	140	222
Cost of natural gas	21	26	81	137
Operation, maintenance and other	1,431	1,422	2,920	2,848
Depreciation and amortization	813	790	1,627	1,567
Property and other taxes	293	279	590	543
Impairment charges	195		198
Total operating expenses	4,344	4,356	8,642	8,979
Gains on Sales of Other Assets and Other, net	5	13	14	27
Operating Income	1,145	1,246	2,478	2,702
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	15	23	23	36
Other income and expenses, net	92	72	171	146
Total other income and expenses	107	95	194	182
Interest Expense	500	403	1,011	806
Income From Continuing Operations Before Income Taxes	752	938	1,661	2,078
Income Tax Expense from Continuing Operations	239	334	452	698
Income from Continuing Operations	513	604	1,209	1,380
(Loss) Income From Discontinued Operations, net of tax	(1)	(57)	2	34
Net income	512	547	1,211	1,414
Less: Net Income Attributable to Noncontrolling Interests	3	4	8	7
Net Income (Loss) Attributable to Parent	509	543	1,203	1,407
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	2	7	2	2
Reclassification into earnings from cash flow hedges		1	2	5
Unrealized (losses) gains on available-for-sale securities	3	(3)	7	(3)
Other Comprehensive Income, net of tax	52	23	93	(110)
Comprehensive Income	564	570	1,304	1,304
Less: Comprehensive Income Attributable to Noncontrolling Interests	6	3	12	2
Comprehensive Income Attributable to Parent	$ 558	$ 567	$ 1,292	$ 1,302
Income from continuing operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 0.74	$ 0.87	$ 1.74	$ 1.96
Diluted (usd per share)	0.74	0.87	1.74	1.96
(Loss) Income from discontinued operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)		(0.09)		0.05
Diluted (usd per share)		(0.09)		0.05
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	0.74	0.78	1.74	2.01
Diluted (usd per share)	$ 0.74	$ 0.78	$ 1.74	$ 2.01
Weighted average shares outstanding
Basic (shares)	689	692	689	700
Diluted (shares)	690	692	689	700
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,675	$ 1,707	$ 3,415	$ 3,608
Operating Expenses
Fuel used in electric generation and purchased power – regulated	389	427	810	1,005
Operation, maintenance and other	476	469	988	958
Depreciation and amortization	275	261	534	510
Property and other taxes	71	67	138	137
Total operating expenses	1,211	1,224	2,470	2,610
Operating Income	464	483	945	998
Other Income and Expenses
Other income and expenses, net	45	41	82	83
Interest Expense	107	106	214	208
Income From Continuing Operations Before Income Taxes	402	418	813	873
Income Tax Expense from Continuing Operations	141	153	281	316
Net Income (Loss) Attributable to Parent	261	265	532	557
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges			1
Other Comprehensive Income, net of tax			1
Comprehensive Income Attributable to Parent	261	265	533	557
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,348	2,476	4,680	5,012
Operating Expenses
Fuel used in electric generation and purchased power – regulated	852	1,003	1,712	2,035
Operation, maintenance and other	525	568	1,117	1,133
Depreciation and amortization	296	283	586	570
Property and other taxes	120	124	239	235
Impairment charges	1		3
Total operating expenses	1,794	1,978	3,657	3,973
Gains on Sales of Other Assets and Other, net	6	6	12	14
Operating Income	560	504	1,035	1,053
Other Income and Expenses
Other income and expenses, net	28	19	48	46
Interest Expense	160	166	320	334
Income From Continuing Operations Before Income Taxes	428	357	763	765
Income Tax Expense from Continuing Operations	154	140	277	284
Income from Continuing Operations	274	217	486	481
(Loss) Income From Discontinued Operations, net of tax				(1)
Net income	274	217	486	480
Less: Net Income Attributable to Noncontrolling Interests	2	2	5	5
Net Income (Loss) Attributable to Parent	272	215	481	475
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1	1	2	2
Reclassification into earnings from cash flow hedges	2	1	3	(1)
Unrealized (losses) gains on available-for-sale securities		(1)	1	(1)
Other Comprehensive Income, net of tax	3	1	6
Comprehensive Income	277	218	492	480
Less: Comprehensive Income Attributable to Noncontrolling Interests	2	2	5	5
Comprehensive Income Attributable to Parent	275	216	487	475
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,213	1,193	2,520	2,642
Operating Expenses
Fuel used in electric generation and purchased power – regulated	424	449	872	1,024
Operation, maintenance and other	321	362	707	737
Depreciation and amortization	175	163	350	315
Property and other taxes	38	35	79	67
Total operating expenses	958	1,009	2,008	2,143
Gains on Sales of Other Assets and Other, net			1	1
Operating Income	255	184	513	500
Other Income and Expenses
Other income and expenses, net	12	15	29	35
Interest Expense	64	56	127	116
Income From Continuing Operations Before Income Taxes	203	143	415	419
Income Tax Expense from Continuing Operations	72	58	147	151
Net Income (Loss) Attributable to Parent	131	85	268	268
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,133	1,281	2,157	2,367
Operating Expenses
Fuel used in electric generation and purchased power – regulated	429	554	841	1,011
Operation, maintenance and other	199	202	404	390
Depreciation and amortization	122	122	236	256
Property and other taxes	82	88	160	168
Impairment charges	1		3
Total operating expenses	833	966	1,644	1,825
Operating Income	300	315	513	542
Other Income and Expenses
Other income and expenses, net	14	4	19	10
Interest Expense	40	50	81	99
Income From Continuing Operations Before Income Taxes	274	269	451	453
Income Tax Expense from Continuing Operations	103	104	170	175
Net Income (Loss) Attributable to Parent	171	165	281	278
Other Comprehensive Income (Loss), net of tax
Unrealized (losses) gains on available-for-sale securities			1
Other Comprehensive Income, net of tax			1
Comprehensive Income Attributable to Parent	171	165	282	278
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	323	299	663	638
Nonregulated electric and other	6	9	12	23
Regulated natural gas	99	97	269	330
Total operating revenues	428	405	944	991
Operating Expenses
Fuel used in electric generation and purchased power – regulated	100	107	211	222
Fuel used in electric generation and purchased power – nonregulated	13	12	23	26
Cost of natural gas	9	12	58	109
Operation, maintenance and other	122	118	241	246
Depreciation and amortization	64	58	125	115
Property and other taxes	65	57	136	127
Total operating expenses	373	364	794	845
Gains on Sales of Other Assets and Other, net		2	1	8
Operating Income	55	43	151	154
Other Income and Expenses
Other income and expenses, net	1	(5)	3	(2)
Interest Expense	21	18	41	38
Income From Continuing Operations Before Income Taxes	35	20	113	114
Income Tax Expense from Continuing Operations	12	7	33	42
Income from Continuing Operations	23	13	80	72
(Loss) Income From Discontinued Operations, net of tax		(65)	2	25
Net Income (Loss) Attributable to Parent	23	(52)	82	97
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	702	686	1,416	1,474
Operating Expenses
Fuel used in electric generation and purchased power – regulated	220	235	448	529
Operation, maintenance and other	189	180	351	361
Depreciation and amortization	97	107	222	211
Property and other taxes	22	19	45	18
Total operating expenses	528	541	1,066	1,119
Gains on Sales of Other Assets and Other, net		1		1
Operating Income	174	146	350	356
Other Income and Expenses
Other income and expenses, net	6	4	10	9
Interest Expense	47	43	91	88
Income From Continuing Operations Before Income Taxes	133	107	269	277
Income Tax Expense from Continuing Operations	48	39	89	101
Net Income (Loss) Attributable to Parent	85	68	180	176
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges			(1)	(1)
Other Comprehensive Income, net of tax			(1)	(1)
Comprehensive Income Attributable to Parent	$ 85	$ 68	$ 179	$ 175

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income (loss)	$ 512	$ 547	$ 1,211	$ 1,414
Other Comprehensive Income (Loss), net of tax
Foreign currency translation adjustments	58	9	107	(116)
Pension and OPEB adjustments	2	7	2	2
Net unrealized (losses) gains on cash flow hedges	(11)	9	(25)	2
Reclassification into earnings from cash flow hedges		1	2	5
Unrealized gains (losses) on available-for-sale securities	3	(3)	7	(3)
Other Comprehensive Income (Loss), net of tax	52	23	93	(110)
Comprehensive Income	564	570	1,304	1,304
Less: Comprehensive Income Attributable to Noncontrolling Interests	6	3	12	2
Comprehensive Income Attributable to Parent	$ 558	$ 567	$ 1,292	$ 1,302

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 676	$ 857
Receivables (net of allowance for doubtful accounts)	575	703
Receivables of VIEs (net of allowance for doubtful accounts)	1,943	1,748
Inventory	3,627	3,810
Regulatory assets	825	877
Other	451	327
Total current assets	8,097	8,322
Investments and Other Assets
Investments in equity method unconsolidated affiliates	613	499
Nuclear decommissioning trust funds	5,966	5,825
Goodwill	16,357	16,343
Other	2,972	3,042
Total investments and other assets	25,908	25,709
Property, Plant and Equipment
Cost	115,143	112,826
Accumulated depreciation and amortization	(38,412)	(37,665)
Generation facilities to be retired, net	598	548
Net property, plant and equipment	77,329	75,709
Regulatory Assets and Deferred Debits
Regulatory assets	11,290	11,373
Other	30	43
Total regulatory assets and deferred debits	11,320	11,416
Total Assets	122,654	121,156
Current Liabilities
Accounts payable	2,221	2,400
Notes payable and commercial paper	2,312	3,633
Taxes accrued	467	348
Interest accrued	448	430
Current maturities of long-term debt	2,342	2,074
Regulatory liabilities	332	400
Other	1,784	2,115
Total current liabilities	9,906	11,400
Long-Term Debt	39,931	37,495
Deferred Credits and Other Liabilities
Deferred income taxes	13,038	12,705
Investment tax credits	492	472
Accrued pension and other post-retirement benefit costs	1,044	1,088
Asset retirement obligations	10,231	10,264
Regulatory liabilities	6,334	6,255
Other	1,730	1,706
Total deferred credits and other liabilities	32,869	32,490
Commitments and Contingencies
Equity
Common stock	1	1
Additional paid-in capital	37,984	37,968
Retained earnings	2,627	2,564
Accumulated other comprehensive income (loss)	(717)	(806)
Total Duke Energy Corporation stockholders' equity	39,895	39,727
Noncontrolling interests	53	44
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	39,948	39,771
Total Liabilities and Equity	122,654	121,156
Duke Energy Carolinas [Member]
Current Assets
Cash and cash equivalents	16	13
Receivables (net of allowance for doubtful accounts)	112	142
Receivables of VIEs (net of allowance for doubtful accounts)	696	596
Receivables from affiliated companies	71	107
Notes receivable from affiliated companies	252	163
Inventory	1,169	1,276
Regulatory assets	262	305
Other	86	128
Total current assets	2,664	2,730
Investments and Other Assets
Nuclear decommissioning trust funds	3,133	3,050
Other	916	999
Total investments and other assets	4,049	4,049
Property, Plant and Equipment
Cost	40,285	39,398
Accumulated depreciation and amortization	(13,880)	(13,521)
Net property, plant and equipment	26,405	25,877
Regulatory Assets and Deferred Debits
Regulatory assets	2,856	2,766
Other	3	4
Total regulatory assets and deferred debits	2,859	2,770
Total Assets	35,977	35,426
Current Liabilities
Accounts payable	565	753
Accounts payable to affiliated companies	173	229
Taxes accrued	137	25
Interest accrued	108	95
Current maturities of long-term debt	468	356
Regulatory liabilities	91	39
Other	400	519
Total current liabilities	1,942	2,016
Long-Term Debt	8,592	7,711
Long-Term Debt Payable to Affiliated Companies	300	300
Deferred Credits and Other Liabilities
Deferred income taxes	6,472	6,146
Investment tax credits	196	199
Accrued pension and other post-retirement benefit costs	96	107
Asset retirement obligations	3,910	3,918
Regulatory liabilities	2,885	2,802
Other	645	621
Total deferred credits and other liabilities	14,204	13,793
Commitments and Contingencies
Equity
Member's equity	10,949	11,617
Accumulated other comprehensive income (loss)	(10)	(11)
Members' Equity	10,939	11,606
Total Liabilities and Equity	35,977	35,426
Progress Energy [Member]
Current Assets
Cash and cash equivalents	34	44
Receivables (net of allowance for doubtful accounts)	100	151
Receivables of VIEs (net of allowance for doubtful accounts)	776	658
Receivables from affiliated companies	11	375
Inventory	1,725	1,751
Regulatory assets	322	362
Other	168	156
Total current assets	3,136	3,497
Investments and Other Assets
Nuclear decommissioning trust funds	2,834	2,775
Goodwill	3,655	3,655
Other	852	834
Total investments and other assets	7,341	7,264
Property, Plant and Equipment
Cost	43,720	42,666
Accumulated depreciation and amortization	(15,087)	(14,867)
Generation facilities to be retired, net	506	548
Net property, plant and equipment	29,139	28,347
Regulatory Assets and Deferred Debits
Regulatory assets	5,298	5,435
Other	4	5
Total regulatory assets and deferred debits	5,302	5,440
Total Assets	44,918	44,548
Current Liabilities
Accounts payable	690	722
Accounts payable to affiliated companies	232	311
Notes payable to affiliated companies	916	1,308
Taxes accrued	162	53
Interest accrued	185	195
Current maturities of long-term debt	300	315
Regulatory liabilities	166	286
Other	702	891
Total current liabilities	3,353	4,081
Long-Term Debt	15,036	13,999
Long-Term Debt Payable to Affiliated Companies	150	150
Deferred Credits and Other Liabilities
Deferred income taxes	5,044	4,790
Accrued pension and other post-retirement benefit costs	519	536
Asset retirement obligations	5,386	5,369
Regulatory liabilities	2,409	2,387
Other	328	383
Total deferred credits and other liabilities	13,686	13,465
Commitments and Contingencies
Equity
Additional paid-in capital	8,092	8,092
Retained earnings	4,661	4,831
Accumulated other comprehensive income (loss)	(42)	(48)
Total Duke Energy Corporation stockholders' equity	12,711	12,875
Noncontrolling interests	(18)	(22)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	12,693	12,853
Total Liabilities and Equity	44,918	44,548
Duke Energy Progress [Member]
Current Assets
Cash and cash equivalents	8	15
Receivables (net of allowance for doubtful accounts)	35	87
Receivables of VIEs (net of allowance for doubtful accounts)	421	349
Receivables from affiliated companies	9	16
Inventory	1,068	1,088
Regulatory assets	187	264
Other	35	121
Total current assets	1,763	1,940
Investments and Other Assets
Nuclear decommissioning trust funds	2,110	2,035
Other	509	486
Total investments and other assets	2,619	2,521
Property, Plant and Equipment
Cost	27,771	27,313
Accumulated depreciation and amortization	(10,350)	(10,141)
Generation facilities to be retired, net	506	548
Net property, plant and equipment	17,927	17,720
Regulatory Assets and Deferred Debits
Regulatory assets	2,744	2,710
Other	2	3
Total regulatory assets and deferred debits	2,746	2,713
Total Assets	25,055	24,894
Current Liabilities
Accounts payable	300	399
Accounts payable to affiliated companies	134	190
Notes payable to affiliated companies	78	209
Taxes accrued	71	15
Interest accrued	96	96
Current maturities of long-term debt	252	2
Regulatory liabilities	84	85
Other	314	412
Total current liabilities	1,329	1,408
Long-Term Debt	6,163	6,366
Long-Term Debt Payable to Affiliated Companies	150	150
Deferred Credits and Other Liabilities
Deferred income taxes	3,167	3,027
Investment tax credits	152	132
Accrued pension and other post-retirement benefit costs	249	262
Asset retirement obligations	4,594	4,567
Regulatory liabilities	1,901	1,878
Other	23	45
Total deferred credits and other liabilities	10,086	9,911
Commitments and Contingencies
Equity
Member's equity	7,327	7,059
Members' Equity	7,327	7,059
Total Liabilities and Equity	25,055	24,894
Duke Energy Florida [Member]
Current Assets
Cash and cash equivalents	8	8
Receivables (net of allowance for doubtful accounts)	64	60
Receivables of VIEs (net of allowance for doubtful accounts)	355	308
Receivables from affiliated companies	3	84
Inventory	657	663
Regulatory assets	135	98
Other	43	21
Total current assets	1,265	1,242
Investments and Other Assets
Nuclear decommissioning trust funds	724	740
Other	288	292
Total investments and other assets	1,012	1,032
Property, Plant and Equipment
Cost	15,938	15,343
Accumulated depreciation and amortization	(4,730)	(4,720)
Net property, plant and equipment	11,208	10,623
Regulatory Assets and Deferred Debits
Regulatory assets	2,553	2,725
Other	3	2
Total regulatory assets and deferred debits	2,556	2,727
Total Assets	16,041	15,624
Current Liabilities
Accounts payable	390	322
Accounts payable to affiliated companies	100	116
Notes payable to affiliated companies	406	813
Taxes accrued	156	132
Interest accrued	40	43
Current maturities of long-term debt	48	13
Regulatory liabilities	82	200
Other	361	452
Total current liabilities	1,583	2,091
Long-Term Debt	5,492	4,253
Deferred Credits and Other Liabilities
Deferred income taxes	2,571	2,460
Accrued pension and other post-retirement benefit costs	238	242
Asset retirement obligations	792	802
Regulatory liabilities	508	509
Other	103	146
Total deferred credits and other liabilities	4,212	4,159
Commitments and Contingencies
Equity
Member's equity	4,753	5,121
Accumulated other comprehensive income (loss)	1
Members' Equity	4,754	5,121
Total Liabilities and Equity	16,041	15,624
Duke Energy Ohio [Member]
Current Assets
Cash and cash equivalents	10	14
Receivables (net of allowance for doubtful accounts)	63	66
Receivables from affiliated companies	35	84
Notes receivable from affiliated companies	186
Inventory	110	105
Regulatory assets	54	36
Other	65	110
Total current assets	523	415
Investments and Other Assets
Goodwill	920	920
Other	16	20
Total investments and other assets	936	940
Property, Plant and Equipment
Cost	7,906	7,750
Accumulated depreciation and amortization	(2,536)	(2,507)
Net property, plant and equipment	5,370	5,243
Regulatory Assets and Deferred Debits
Regulatory assets	472	497
Other	2	2
Total regulatory assets and deferred debits	474	499
Total Assets	7,303	7,097
Current Liabilities
Accounts payable	218	207
Accounts payable to affiliated companies	76	53
Notes payable to affiliated companies		103
Taxes accrued	108	171
Interest accrued	19	18
Current maturities of long-term debt	54	106
Regulatory liabilities	18	12
Other	82	153
Total current liabilities	575	823
Long-Term Debt	1,808	1,467
Long-Term Debt Payable to Affiliated Companies	25	25
Deferred Credits and Other Liabilities
Deferred income taxes	1,476	1,407
Accrued pension and other post-retirement benefit costs	52	56
Asset retirement obligations	125	125
Regulatory liabilities	241	245
Other	160	165
Total deferred credits and other liabilities	2,054	1,998
Commitments and Contingencies
Equity
Common stock	762	762
Additional paid-in capital	2,695	2,720
Retained earnings	(616)	(698)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,841	2,784
Total Liabilities and Equity	7,303	7,097
Duke Energy Indiana [Member]
Current Assets
Cash and cash equivalents	12	9
Receivables (net of allowance for doubtful accounts)	87	96
Receivables from affiliated companies	60	71
Notes receivable from affiliated companies	147	83
Inventory	508	570
Regulatory assets	115	102
Other	45	15
Total current assets	974	946
Investments and Other Assets
Total investments and other assets	221	212
Property, Plant and Equipment
Cost	13,677	14,007
Accumulated depreciation and amortization	(4,219)	(4,484)
Generation facilities to be retired, net	93
Net property, plant and equipment	9,551	9,523
Regulatory Assets and Deferred Debits
Regulatory assets	825	716
Other	2	2
Total regulatory assets and deferred debits	827	718
Total Assets	11,573	11,399
Current Liabilities
Accounts payable	146	189
Accounts payable to affiliated companies	87	83
Taxes accrued	40	89
Interest accrued	59	56
Current maturities of long-term debt	221	547
Regulatory liabilities	57	62
Other	101	97
Total current liabilities	711	1,123
Long-Term Debt	3,566	3,071
Long-Term Debt Payable to Affiliated Companies	150	150
Deferred Credits and Other Liabilities
Deferred income taxes	1,732	1,657
Investment tax credits	137	138
Accrued pension and other post-retirement benefit costs	74	80
Asset retirement obligations	520	525
Regulatory liabilities	745	754
Other	72	65
Total deferred credits and other liabilities	3,280	3,219
Commitments and Contingencies
Equity
Member's equity	3,866
Common stock		1
Additional paid-in capital		1,384
Retained earnings		2,450
Accumulated other comprehensive income (loss)		1
Members' Equity	3,866
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		3,836
Total Liabilities and Equity	$ 11,573	$ 11,399

Condensed Consolidated Balance5

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Receivables, allowance for doubtful accounts	$ 23	$ 18
Receivables of VIEs, allowance for doubtful accounts	56	53
Regulatory assets	825	877
Regulatory assets	11,290	11,373
Current maturities of long-term debt	2,342	2,074
Long-term Debt of VIEs	$ 39,931	$ 37,495
Common stock, par or stated value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	689,000,000	688,000,000
Variable Interest Entity [Member]
Regulatory assets	$ 34
Regulatory assets	1,194
Current maturities of long-term debt	197	$ 125
Long-term Debt of VIEs	3,383	2,197
Duke Energy Carolinas [Member]
Receivables, allowance for doubtful accounts	2	3
Receivables of VIEs, allowance for doubtful accounts	7	7
Regulatory assets	262	305
Regulatory assets	2,856	2,766
Current maturities of long-term debt	468	356
Long-term Debt of VIEs	8,592	7,711
Progress Energy [Member]
Receivables, allowance for doubtful accounts	6	6
Receivables of VIEs, allowance for doubtful accounts	8	8
Regulatory assets	322	362
Regulatory assets	5,298	5,435
Current maturities of long-term debt	300	315
Long-term Debt of VIEs	$ 15,036	$ 13,999
Common stock, par or stated value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Progress Energy [Member] | Variable Interest Entity [Member]
Regulatory assets	$ 34
Regulatory assets	1,194
Current maturities of long-term debt	35
Long-term Debt of VIEs	1,768	$ 479
Duke Energy Progress [Member]
Receivables, allowance for doubtful accounts	4	4
Receivables of VIEs, allowance for doubtful accounts	5	5
Regulatory assets	187	264
Regulatory assets	2,744	2,710
Current maturities of long-term debt	252	2
Long-term Debt of VIEs	6,163	6,366
Duke Energy Florida [Member]
Receivables, allowance for doubtful accounts	2	2
Receivables of VIEs, allowance for doubtful accounts	3	3
Regulatory assets	135	98
Regulatory assets	2,553	2,725
Current maturities of long-term debt	48	13
Long-term Debt of VIEs	5,492	4,253
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Regulatory assets	34
Regulatory assets	1,194
Current maturities of long-term debt	35
Long-term Debt of VIEs	1,468	225
Duke Energy Ohio [Member]
Receivables, allowance for doubtful accounts	2	2
Regulatory assets	54	36
Regulatory assets	472	497
Current maturities of long-term debt	54	106
Long-term Debt of VIEs	$ 1,808	$ 1,467
Common stock, par or stated value	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	89,663,086	89,663,086
Duke Energy Indiana [Member]
Receivables, allowance for doubtful accounts	$ 1	$ 1
Regulatory assets	115	102
Regulatory assets	825	716
Current maturities of long-term debt	221	547
Long-term Debt of VIEs	$ 3,566	$ 3,071
Common stock, par or stated value		$ 0.01
Common stock, shares authorized		60,000,000
Common stock, shares outstanding		53,913,701

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 1,211	$ 1,414
Net Income Attributable to Parent	1,203	1,407
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,868	1,784
Equity component of AFUDC	(87)	(82)
Gains on sales of other assets	(18)	(29)
Impairment charges	198	37
Deferred income taxes	285	699
Equity in earnings of unconsolidated affiliates	(23)	(36)
Accrued pension and other post-retirement benefit costs	8	36
Contributions to qualified pension plans		(132)
Payments for asset retirement obligations	(263)	(125)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	199	(29)
Receivables	(57)	105
Inventory	178	2
Other current assets	(51)	(161)
Increase (decrease) in
Accounts payable	(153)	(288)
Taxes accrued	216	(29)
Other current liabilities	(281)	(145)
Other assets	(9)	(63)
Other liabilities	(15)	(79)
Net cash provided by operating activities	3,206	2,879
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(3,393)	(3,062)
Investment expenditures	(136)	(98)
Acquisitions		(29)
Purchases of available-for-sale securities	(3,033)	(2,187)
Proceeds from sales and maturities of available-for-sale securities	3,059	2,200
Net proceeds from the sale of the Disposal Group		2,792
Net proceeds from the sales of equity investments and other assets	2	40
Change in restricted cash	(21)	(3)
Other	(86)	53
Net cash used in investing activities	(3,608)	(294)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	3,514	574
Proceeds from the issuance of common stock related to employee benefit plans	7	16
Payments for the redemption of long-term debt	(795)	(1,246)
Proceeds from issuance of short-term debt with original maturities greater than 90 days	500	287
Payments for the redemption of short-term debt with original maturities greater than 90 days	(492)	(664)
Notes payable and commercial paper	(1,349)	12
Distributions to noncontrolling interests	(3)	(7)
Dividends paid	(1,140)	(1,115)
Repurchase of common shares		(1,500)
Other	(21)	(18)
Net cash provided by (used in) financing activities	221	(3,661)
Net increase (decrease) in cash and cash equivalents	(181)	(1,076)
Cash and cash equivalents at beginning of period	857	2,036
Cash and cash equivalents at end of period	676	960
Significant non-cash transactions:
Accrued capital expenditures	670	547
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income Attributable to Parent	532	557
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	673	670
Equity component of AFUDC	(48)	(48)
Deferred income taxes	273	184
Accrued pension and other post-retirement benefit costs	2	7
Contributions to qualified pension plans		(42)
Payments for asset retirement obligations	(118)	(60)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	3
Receivables	(48)	45
Receivable from affiliated companies	36	(31)
Inventory	102	(31)
Other current assets	24	34
Increase (decrease) in
Accounts payable	(226)	(200)
Accounts payable to affiliated companies	(56)	(13)
Taxes accrued	188	73
Other current liabilities	28	(33)
Other assets	22	58
Other liabilities	(14)	(49)
Net cash provided by operating activities	1,373	1,121
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,031)	(954)
Purchases of available-for-sale securities	(1,395)	(1,410)
Proceeds from sales and maturities of available-for-sale securities	1,395	1,410
Notes receivable from affiliated companies payments	(89)	(550)
Other	(41)	8
Net cash used in investing activities	(1,161)	(1,496)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	992	496
Payments for the redemption of long-term debt	(1)
Distributions to parent	(1,200)	(100)
Other		(6)
Net cash provided by (used in) financing activities	(209)	390
Net increase (decrease) in cash and cash equivalents	3	15
Cash and cash equivalents at beginning of period	13	13
Cash and cash equivalents at end of period	16	28
Significant non-cash transactions:
Accrued capital expenditures	228	160
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	486	480
Net Income Attributable to Parent	481	475
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	696	648
Equity component of AFUDC	(30)	(26)
Gains on sales of other assets	(15)	(14)
Impairment charges	3
Deferred income taxes	285	358
Accrued pension and other post-retirement benefit costs	(12)	(3)
Contributions to qualified pension plans		(42)
Payments for asset retirement obligations	(126)	(61)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	32	5
Receivables	(66)	(103)
Receivable from affiliated companies	306	(55)
Inventory	25	62
Other current assets	45	215
Increase (decrease) in
Accounts payable	(26)	(182)
Accounts payable to affiliated companies	(79)	68
Taxes accrued	90	94
Other current liabilities	(162)	(9)
Other assets	(72)	(70)
Other liabilities	15	(32)
Net cash provided by operating activities	1,395	1,333
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,441)	(1,170)
Purchases of available-for-sale securities	(1,570)	(562)
Proceeds from sales and maturities of available-for-sale securities	1,594	624
Proceeds from Insurance	58
Notes receivable from affiliated companies		220
Change in restricted cash	(6)
Other	(14)	4
Net cash used in investing activities	(1,379)	(884)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,338
Payments for the redemption of long-term debt	(320)	(549)
Notes payable to affiliated companies	(392)	110
Distributions to noncontrolling interests	(1)	(4)
Dividends to parent	(651)
Other		(3)
Net cash provided by (used in) financing activities	(26)	(446)
Net increase (decrease) in cash and cash equivalents	(10)	3
Cash and cash equivalents at beginning of period	44	42
Cash and cash equivalents at end of period	34	45
Significant non-cash transactions:
Accrued capital expenditures	288	271
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income Attributable to Parent	268	268
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	451	389
Equity component of AFUDC	(20)	(23)
Gains on sales of other assets	(3)	(1)
Deferred income taxes	172	177
Accrued pension and other post-retirement benefit costs	(16)	(7)
Contributions to qualified pension plans		(21)
Payments for asset retirement obligations	(100)	(32)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(1)	(3)
Receivables	(19)	(64)
Receivable from affiliated companies	7	6
Inventory	20	53
Other current assets	131	156
Increase (decrease) in
Accounts payable	(28)	(128)
Accounts payable to affiliated companies	(56)	62
Taxes accrued	56	66
Other current liabilities	(12)	(15)
Other assets	(26)	(31)
Other liabilities	(6)	(21)
Net cash provided by operating activities	818	831
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(704)	(699)
Purchases of available-for-sale securities	(1,299)	(319)
Proceeds from sales and maturities of available-for-sale securities	1,284	301
Notes receivable from affiliated companies		237
Other	(19)	6
Net cash used in investing activities	(738)	(474)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	59
Payments for the redemption of long-term debt	(15)	(544)
Notes payable to affiliated companies	(131)	192
Other		(1)
Net cash provided by (used in) financing activities	(87)	(353)
Net increase (decrease) in cash and cash equivalents	(7)	4
Cash and cash equivalents at beginning of period	15	9
Cash and cash equivalents at end of period	8	13
Significant non-cash transactions:
Accrued capital expenditures	73	135
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income Attributable to Parent	281	278
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	239	258
Equity component of AFUDC	(9)	(2)
Impairment charges	3
Deferred income taxes	113	237
Accrued pension and other post-retirement benefit costs	1	3
Contributions to qualified pension plans		(21)
Payments for asset retirement obligations	(25)	(28)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	34	5
Receivables	(49)	(40)
Receivable from affiliated companies	23	(53)
Inventory	5	10
Other current assets	(13)	10
Increase (decrease) in
Accounts payable	3	(53)
Accounts payable to affiliated companies	(16)	3
Taxes accrued	5	65
Other current liabilities	(142)	5
Other assets	(47)	(44)
Other liabilities	20	(19)
Net cash provided by operating activities	426	614
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(737)	(471)
Purchases of available-for-sale securities	(271)	(243)
Proceeds from sales and maturities of available-for-sale securities	310	323
Proceeds from Insurance	58
Change in restricted cash	(6)
Other	5	1
Net cash used in investing activities	(641)	(390)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,278
Payments for the redemption of long-term debt	(5)	(5)
Notes payable to affiliated companies	(407)	137
Dividends to parent		(350)
Distributions to parent	(649)
Other	(2)	(1)
Net cash provided by (used in) financing activities	215	(219)
Net increase (decrease) in cash and cash equivalents		5
Cash and cash equivalents at beginning of period	8	8
Cash and cash equivalents at end of period	8	13
Significant non-cash transactions:
Accrued capital expenditures	215	136
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income Attributable to Parent	82	97
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	127	117
Equity component of AFUDC	(2)	(2)
Gains on sales of other assets	(1)	(8)
Impairment charges		40
Deferred income taxes	68	62
Accrued pension and other post-retirement benefit costs	3	4
Contributions to qualified pension plans		(1)
Payments for asset retirement obligations	(3)	(1)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(2)	(12)
Receivables	3	6
Receivable from affiliated companies	49	46
Inventory	(5)	3
Other current assets	49	32
Increase (decrease) in
Accounts payable	8	(12)
Accounts payable to affiliated companies	23	19
Taxes accrued	(68)	(68)
Other current liabilities	(66)	99
Other assets	(8)	19
Other liabilities	(9)	(52)
Net cash provided by operating activities	248	388
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(214)	(166)
Notes receivable from affiliated companies payments	(186)
Notes receivable from affiliated companies		130
Other	(13)	(4)
Net cash used in investing activities	(413)	(40)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	341
Payments for the redemption of long-term debt	(52)	(152)
Notes payable to affiliated companies	(103)	(193)
Dividends to parent	(25)
Other		(1)
Net cash provided by (used in) financing activities	161	(346)
Net increase (decrease) in cash and cash equivalents	(4)	2
Cash and cash equivalents at beginning of period	14	20
Cash and cash equivalents at end of period	10	22
Significant non-cash transactions:
Accrued capital expenditures	30	19
Distribution of membership interest of Duke Energy SAM, LLC to parent		1,912
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income Attributable to Parent	180	176
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	223	214
Equity component of AFUDC	(7)	(6)
Gains on sales of other assets		(1)
Deferred income taxes	36	232
Accrued pension and other post-retirement benefit costs	4	6
Contributions to qualified pension plans		(9)
Payments for asset retirement obligations	(16)	(3)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		(2)
Receivables	12	(1)
Receivable from affiliated companies	11	6
Inventory	62	(42)
Other current assets	(19)	87
Increase (decrease) in
Accounts payable	(22)	26
Accounts payable to affiliated companies	4	2
Taxes accrued	(42)	(21)
Other current liabilities	(60)	5
Other assets	(29)	(31)
Other liabilities	44	(43)
Net cash provided by operating activities	381	595
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(325)	(380)
Purchases of available-for-sale securities	(7)	(4)
Proceeds from sales and maturities of available-for-sale securities	5	3
Net proceeds from the sales of equity investments and other assets		14
Notes receivable from affiliated companies payments	(64)	(25)
Other	(6)	25
Net cash used in investing activities	(397)	(367)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	495
Payments for the redemption of long-term debt	(326)
Notes payable to affiliated companies		(71)
Dividends to parent		(150)
Distributions to parent	(149)
Other	(1)	(1)
Net cash provided by (used in) financing activities	19	(222)
Net increase (decrease) in cash and cash equivalents	3	6
Cash and cash equivalents at beginning of period	9	6
Cash and cash equivalents at end of period	12	12
Significant non-cash transactions:
Accrued capital expenditures	$ 43	$ 46

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Foreign Currency Translation Adjustments [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Net Gains (Losses) on Available for Sale Securities [Member]	Pension and OPEB Related Adjustments [Member]	Common Stockholders' Equity [Member]	Noncontrolling Interest [Member]		Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member]Members Equity [Member]	Duke Energy Carolinas [Member]Net Gains (Losses) on Cash Flow Hedges [Member]	Duke Energy Carolinas [Member]Net Gains (Losses) on Available for Sale Securities [Member]	Progress Energy [Member]	Progress Energy [Member]Additional Paid-in Capital [Member]	Progress Energy [Member]Retained Earnings [Member]	Progress Energy [Member]Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member]Net Gains (Losses) on Available for Sale Securities [Member]	Progress Energy [Member]Pension and OPEB Related Adjustments [Member]	Progress Energy [Member]Common Stockholders' Equity [Member]	Progress Energy [Member]Noncontrolling Interest [Member]	Duke Energy Progress [Member]	Duke Energy Progress [Member]Common Stock [Member]	Duke Energy Progress [Member]Retained Earnings [Member]	Duke Energy Progress [Member]Members Equity [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member]Common Stock [Member]	Duke Energy Florida [Member]Retained Earnings [Member]	Duke Energy Florida [Member]Members Equity [Member]	Duke Energy Florida [Member]Net Gains (Losses) on Available for Sale Securities [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member]Common Stock [Member]	Duke Energy Ohio [Member]Additional Paid-in Capital [Member]	Duke Energy Ohio [Member]Retained Earnings [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member]Common Stock [Member]	Duke Energy Indiana [Member]Additional Paid-in Capital [Member]	Duke Energy Indiana [Member]Retained Earnings [Member]	Duke Energy Indiana [Member]Members Equity [Member]	Duke Energy Indiana [Member]Net Gains (Losses) on Cash Flow Hedges [Member]
Balance at Dec. 31, 2014	$ 40,899	$ 1	$ 39,405	$ 2,012	$ (439)	$ (59)	$ 3	$ (48)	$ 40,875	$ 24						$ 11,176	$ 7,467	$ 3,782	$ (35)	$ 1	$ (7)	$ 11,208	$ (32)	$ 5,867	$ 2,159	$ 3,708		$ 5,222	$ 1,762	$ 3,460			$ 4,674	$ 762	$ 4,782	$ (870)	$ 3,848	$ 1	$ 1,384	$ 2,460		$ 3
Balance, in shares at Dec. 31, 2014		707,000,000
Beginning member's equity at Dec. 31, 2014												$ 10,924	$ 10,937	$ (12)	$ (1)
Net Income	1,414			1,407					1,407	7						480		475				475	5
Net Income Attributable to Parent	1,407											557	557			475								268		268		278		278			97			97	176			176
Distribution of membership interest of Duke Energy SAM, LLC to parent																																	(1,912)		(1,912)
Other comprehensive (loss) income, net of tax	(110)				(111)	7	(3)	2	(105)	(5)									(1)	(1)	2																(1)					(1)
Common stock issuances, including dividend reinvestment and employee benefits, shares		1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	28		28						28
Stock Repurchased During Period, Shares		(20,000,000)
Stock Repurchased During Period, Value	(1,500)		(1,500)						(1,500)
Common stock dividends	(1,115)			(1,115)					(1,115)																			(350)		(350)							(150)			(150)
Distributions to parent												(100)	(100)
Distributions to noncontrolling interest in subsidiaries	(7)									(7)						(4)							(4)
Other	8			(10)					(10)	18	[1]					2		(2)				(2)	4
Balance at Jun. 30, 2015	39,617	$ 1	37,933	2,294	(550)	(52)		(46)	39,580	37						11,654	7,467	4,255	(36)		(5)	11,681	(27)	6,135	$ 2,159	$ 3,976		5,150	$ 1,762	$ 3,388			2,859	762	2,870	(773)	3,873	1	1,384	2,486		2
Balance, in shares at Jun. 30, 2015		688,000,000
Ending member's equity at Jun. 30, 2015												11,381	11,394	(12)	$ (1)
Balance at Dec. 31, 2015	$ 39,771	$ 1	37,968	2,564	(692)	(50)	(3)	(61)	39,727	44						$ 12,853	8,092	4,831	(31)		(17)	12,875	(22)										$ 2,784	762	2,720	(698)	$ 3,836	1	1,384	2,450		1
Balance, in shares at Dec. 31, 2015	688,000,000	688,000,000														100																	89,663,086				53,913,701
Beginning member's equity at Dec. 31, 2015												11,606	11,617	(11)										7,059			$ 7,059	5,121			$ 5,121
Net Income	$ 1,211			1,203					1,203	8						$ 486		481				481	5
Net Income Attributable to Parent	1,203											532	532			481								268			268	281			281		$ 82			82	$ 180				$ 180
Other comprehensive (loss) income, net of tax	93				103	(23)	7	2	89	4		1		1		6			3	1	2	6						1				$ 1					(1)					$ (1)
Common stock issuances, including dividend reinvestment and employee benefits, shares		1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	16		16						16
Common stock dividends	(1,140)			(1,140)					(1,140)							(651)		(651)				(651)											(25)		(25)
Distributions to parent												(1,200)	(1,200)															(649)			(649)						(149)				(149)
Distributions to noncontrolling interest in subsidiaries	(3)									(3)						(1)							(1)
Other																																						$ (1)	$ (1,384)	$ (2,450)	3,835
Balance at Jun. 30, 2016	$ 39,948	$ 1	$ 37,984	$ 2,627	$ (589)	$ (73)	$ 4	$ (59)	$ 39,895	$ 53						$ 12,693	$ 8,092	$ 4,661	$ (28)	$ 1	$ (15)	$ 12,711	$ (18)										$ 2,841	$ 762	$ 2,695	$ (616)
Balance, in shares at Jun. 30, 2016	689,000,000	689,000,000														100																	89,663,086
Ending member's equity at Jun. 30, 2016												$ 10,939	$ 10,949	$ (10)										$ 7,327			$ 7,327	$ 4,754			$ 4,753	$ 1					$ 3,866				$ 3,866
[1]	The $18 million change in Noncontrolling Interests is primarily related to an acquisition of majority interest in a solar company for an insignificant amount of cash consideration.

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Organization and Basis of Presentation	Index to Combined Notes to Condensed Consolidated Financial Statements The unaudited notes to the condensed consolidated financial statements that follow are a combined presentation. The following list indicates the registrants to which the footnotes apply. Tables within the notes may not sum across due to Progress Energy's consolidation of Duke Energy Progress, Duke Energy Florida and other subsidiaries that are not registrants. In addition, the Duke Energy amounts include balances from subsidiaries that are not registrants. Applicable Notes Registrant 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Duke Energy Corporation • • • • • • • • • • • • • • • • Duke Energy Carolinas, LLC • • • • • • • • • • • • • Progress Energy, Inc. • • • • • • • • • • • • • • • Duke Energy Progress, LLC • • • • • • • • • • • • • • Duke Energy Florida, LLC • • • • • • • • • • • • • Duke Energy Ohio, Inc. • • • • • • • • • • • • • • Duke Energy Indiana, LLC • • • • • • • • • • • • • ORGANIZATION AND BASIS OF PRESENTATION NATURE OF OPERATIONS AND BASIS OF CONSOLIDATION Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) and Latin America primarily through its direct and indirect subsidiaries. Duke Energy’s subsidiaries include its subsidiary registrants, Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, LLC (Duke Energy Progress); Duke Energy Florida, LLC (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio) and Duke Energy Indiana, LLC (Duke Energy Indiana, formerly Duke Energy Indiana, Inc.). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its six separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants (Duke Energy Registrants). These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC. Substantially all of Duke Energy Carolinas’ operations qualify for regulatory accounting. Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by the FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida. Substantially all of Progress Energy’s operations qualify for regulatory accounting. Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC. Substantially all of Duke Energy Progress’ operations qualify for regulatory accounting. Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC. Substantially all of Duke Energy Florida’s operations qualify for regulatory accounting. Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in portions of Ohio and Kentucky, the generation and sale of electricity in portions of Kentucky, and the transportation and sale of natural gas in portions of Ohio and Kentucky. Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers and recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). References herein to Duke Energy Ohio collectively include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC. On April 2, 2015, Duke Energy completed the sale of its nonregulated Midwest generation business, which sold power into wholesale energy markets, to a subsidiary of Dynegy Inc. (Dynegy). See Note 2 for additional information. Substantially all of Duke Energy Ohio’s operations that remain after the sale qualify for regulatory accounting. Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC. Substantially all of Duke Energy Indiana’s operations qualify for regulatory accounting. On January 1, 2016, Duke Energy Indiana, an Indiana corporation, converted into an Indiana limited liability company. BASIS OF PRESENTATION Duke Energy completed the sale of Duke Energy Ohio's nonregulated Midwest generation business and Duke Energy Retail Sales (collectively, the Disposal Group), a retail sales business owned by Duke Energy, to Dynegy on April 2, 2015. The results of operations of these businesses prior to the date of sale have been classified as Discontinued Operations on the Condensed Consolidated Statements of Operations. Duke Energy has elected to present cash flows of discontinued operations combined with cash flows of continuing operations. Unless otherwise noted, the notes to these Condensed Consolidated Financial Statements exclude amounts related to discontinued operations. See Note 2 for additional information. These Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles (GAAP) in the U.S. for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP in the U.S. for annual financial statements. Since the interim Condensed Consolidated Financial Statements and Notes do not include all information and notes required by GAAP in the U.S. for annual financial statements, the Condensed Consolidated Financial Statements and other information included in this quarterly report should be read in conjunction with the Consolidated Financial Statements and Notes in the Duke Energy Registrants’ combined Annual Report on Form 10-K for the year ended December 31, 2015 . The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself. These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors. In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. Certain prior year amounts have been reclassified to conform to the current year presentation. UNBILLED REVENUE Revenues on sales of electricity and natural gas are recognized when service is provided or the product is delivered. Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules. Unbilled revenues, which are included within Receivables and Receivables of variable interest entities (VIEs) on the Condensed Consolidated Balance Sheets, are presented in the following table. (in millions) June 30, 2016 December 31, 2015 Duke Energy $ 840 $ 748 Duke Energy Carolinas 330 283 Progress Energy 209 172 Duke Energy Progress 104 102 Duke Energy Florida 105 70 Duke Energy Ohio 2 3 Duke Energy Indiana 38 31 Additionally, Duke Energy Ohio and Duke Energy Indiana sell nearly all of their retail accounts receivable to an affiliate, Cinergy Receivables Company, LLC (CRC), on a revolving basis. These transfers of receivables are accounted for as sales and include receivables for unbilled revenues. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 12 for further information. These receivables for unbilled revenues are shown in the table below. (in millions) June 30, 2016 December 31, 2015 Duke Energy Ohio $ 70 $ 71 Duke Energy Indiana 109 97 AMOUNTS ATTRIBUTABLE TO CONTROLLING INTERESTS Income (Loss) from Discontinued Operations, net of tax presented on the respective Condensed Consolidated Statements of Operations for Duke Energy and Progress Energy is attributable only to controlling interests for all periods presented. Other comprehensive income reported on the Condensed Consolidated Statements of Changes in Equity for Progress Energy is attributable only to controlling interests for all periods presented. EXCISE TAXES Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, excise taxes are accounted for net. Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes on the Condensed Consolidated Statements of Operations were as follows. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy $ 87 $ 97 $ 178 $ 197 Duke Energy Carolinas 7 9 15 18 Progress Energy 50 57 96 106 Duke Energy Progress 4 4 9 8 Duke Energy Florida 46 53 87 98 Duke Energy Ohio 22 23 51 55 Duke Energy Indiana 8 8 16 18 NEW ACCOUNTING STANDARDS The new accounting standards adopted for 2016 and 2015 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. The following accounting standard was adopted by the Duke Energy Registrants during 2015. Balance Sheet Presentation of Debt Issuance Costs. In April and August of 2015, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for the presentation of debt issuance costs. The core principle of this revised accounting guidance is that debt issuance costs are not assets, but adjustments to the carrying cost of debt. For Duke Energy, this revised accounting guidance was adopted retrospectively. The implementation of this accounting standard resulted in a reduction of Other within Regulatory Assets and Deferred Debits and in Long-Term Debt of $ 192 million and $ 170 million on the Condensed Consolidated Balance Sheets as of June 30, 2016, and December 31, 2015, respectively. The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by Duke Energy, as of June 30, 2016 . Revenue from Contracts with Customers. In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. For Duke Energy, the revised accounting guidance is effective for interim and annual periods beginning January 1, 2018. The guidance can be applied retrospectively to all prior reporting periods presented or retrospectively with a cumulative effect as of the initial date of application. Duke Energy is currently evaluating the requirements. The ultimate impact of the new standard has not yet been determined. Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet. For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2019, although it can be early adopted. The guidance is applied using a modified retrospective approach. Duke Energy is currently evaluating the requirements. Other than an expected increase in assets and liabilities, the ultimate impact of the new standard has not yet been determined. Stock-Based Compensation and Income Taxes. In March 2016, the FASB issued revised accounting guidance for stock-based compensation and the associated income taxes. This standard changes certain aspects of accounting for stock-based payment awards to employees including the accounting for income taxes, statutory tax withholding requirements, as well as the classification on the Condensed Consolidated Statements of Cash Flows. This guidance will be applied prospectively, retrospectively, or using a modified retrospective transition method depending on the item changed. For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2017, although it can be early adopted. Duke Energy is currently evaluating the requirements. The primary change expected is an increase in the volatility of income tax expense.

Acquisitions and Dispositions

Acquisitions and Dispositions	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS ACQUISITIONS The Duke Energy Registrants consolidate assets and liabilities from acquisitions as of the purchase date, and include earnings from acquisitions in consolidated earnings after the purchase date. Acquisition of Piedmont Natural Gas On October 24, 2015, Duke Energy entered into an Agreement and Plan of Merger (Merger Agreement) with Piedmont Natural Gas Company, Inc. (Piedmont), a North Carolina corporation. Under the terms of the Merger Agreement, Duke Energy will acquire Piedmont for approximately $4.9 billion in cash and Piedmont will become a wholly owned subsidiary of Duke Energy. In addition, Duke Energy will assume Piedmont's existing debt, which was approximately $2.0 billion at April 30, 2016, the end of Piedmont's most recent filed quarter. The excess of the purchase price over the fair value of Piedmont's assets and liabilities on the acquisition date will be recorded as goodwill. Duke Energy estimates the transaction would result in incremental goodwill of approximately $3.5 billion . Duke Energy expects to finance the transaction with a combination of debt, equity issuances and other cash sources. As of June 30, 2016 , Duke Energy had entered into $1.4 billion of forward-starting interest rate swaps to manage interest rate exposure for the expected financing of the Piedmont acquisition. For additional information on the forward-starting swaps, see Note 9 . In March 2016, Duke Energy marketed an equity offering of 10.6 million shares of common stock. In lieu of issuing equity at the time of the offering, Duke Energy entered into equity forward sale agreements (the Equity Forwards) with Barclays Capital, Inc. (Barclays). Duke Energy expects to settle the Equity Forwards on or around the closing date of the Piedmont acquisition. The net proceeds received upon settlement are expected to be used to finance a portion of the acquisition of Piedmont. For additional information regarding the Equity Forwards, see Note 13 . In connection with the Merger Agreement with Piedmont, Duke Energy entered into a $4.9 billion senior unsecured bridge financing facility (Bridge Facility) with Barclays. The Bridge Facility, if drawn upon, may be used to (i) fund the cash consideration for the transaction and (ii) pay certain fees and expenses in connection with the transaction. In November 2015, Barclays syndicated its commitment under the Bridge Facility to a broader group of lenders. Duke Energy does not expect to draw upon the Bridge Facility. The amount of the Bridge Facility is reduced by any financings related to the Piedmont acquisition entered into by Duke Energy, and has accordingly been reduced to approximately $3.2 billion as a result of the Equity Forwards and $1 billion of the commitments under a term loan amended and restated as of August 1, 2016. See Note 6, Term Loan Facility, for more information. Piedmont's shareholders have approved the company's acquisition by Duke Energy and the Federal Trade Commission (FTC) has granted early termination of the 30-day waiting period under the federal Hart-Scott-Rodino Antitrust Improvements Act of 1976. On January 15, 2016, Duke Energy and Piedmont filed an application with the NCUC for approval of the proposed business combination and associated financing transactions. On January 29, 2016, the NCUC approved Duke Energy's proposed financing transactions. On March 7, 2016, the KPSC granted Duke Energy's declaratory request that the transaction does not constitute a change in control and does not require KPSC approval. The Tennessee Regulatory Authority approved Duke Energy's and Piedmont's request of the change in control resulting from the transaction at its March 14, 2016, meeting. On June 10, 2016 the North Carolina Public Staff reached an agreement with Duke Energy and Piedmont on certain stipulations and conditions for approval of the transaction. Duke Energy and Piedmont have also entered into settlement agreements with the Environmental Defense Fund (EDF) and the Carolina Utility Customers Association, Inc. (CUCA) resolving EDF's and CUCA's issues in the case. On July 19, 2016, the NCUC concluded an evidentiary hearing for the proposed business combination. Proposed orders are due from all parties by August 25, 2016, after which the NCUC will rule on the application. Subject to receipt of NCUC approval and meeting closing conditions, Duke Energy and Piedmont expect to close the transaction by the end of 2016. The Merger Agreement contains certain termination rights for both Duke Energy and Piedmont, and provides that, upon termination of the Merger Agreement under specified circumstances, Duke Energy would be required to pay a termination fee of $250 million to Piedmont and Piedmont would be required to pay Duke Energy a termination fee of $125 million . See Note 4 for additional information regarding Duke Energy and Piedmont's joint investment in Atlantic Coast Pipeline, LLC (ACP). Purchase of NCEMPA's Generation On July 31, 2015, Duke Energy Progress completed the purchase of North Carolina Eastern Municipal Power Agency’s (NCEMPA) ownership interests in certain generating assets, fuel and spare parts inventory jointly owned with and operated by Duke Energy Progress for approximately $1.25 billion . This purchase was accounted for as an asset acquisition. The purchase resulted in the acquisition of a total of approximately 700 megawatts (MW) of generating capacity at Brunswick Nuclear Plant, Shearon Harris Nuclear Plant, Mayo Steam Plant and Roxboro Steam Plant. In connection with this transaction, Duke Energy Progress and NCEMPA entered into a 30-year wholesale power agreement, whereby Duke Energy Progress will sell power to NCEMPA to continue to meet the needs of NCEMPA customers. The purchase price exceeded the historical carrying value of the acquired assets by $350 million , which was recognized as an acquisition adjustment and recorded in property, plant and equipment. Duke Energy Progress established a rider in North Carolina to recover the costs to acquire, operate and maintain interests in the assets purchased as allocated to its North Carolina retail operations, including the purchase acquisition adjustment, and included the purchase acquisition adjustment in wholesale power formula rates. Duke Energy Progress received an order from the PSCSC to defer the recovery of the South Carolina retail allocated costs of the asset purchased until the Duke Energy Progress' next general rate case, which was filed in July 2016. See Note 4, for additional information on the South Carolina Rate Case. DISPOSITIONS Potential Sale of International Energy In February 2016, Duke Energy announced it had initiated a process to divest the International Energy business segment, excluding the equity method investment in National Methanol Company (NMC). Duke Energy is actively marketing the business. Non-binding offers have been received and are being evaluated. There is no assurance that this process will result in a transaction and the timing for execution of a potential transaction is uncertain. Proceeds from a successful sale would be used by Duke Energy to reduce debt and fund the operations and growth of domestic businesses. If the potential of a sale were to progress, it could result in classification of International Energy as assets held for sale and as a discontinued operation. Based upon the advancement of the marketing efforts, Duke Energy performed recoverability tests of the long-lived asset groups of International Energy as of June 30, 2016. As a result, Duke Energy determined the carrying value of certain assets in Central America is not fully recoverable and recorded a pretax impairment charge of $194 million , which is included within Impairment Charges on the Condensed Consolidated Statements of Operations for the three and six months ended June 30, 2016. The impairment charge represents the excess of carrying value over the estimated fair value of the assets. The fair value of the assets was primarily determined from the income approach using discounted cash flows but also considered market information obtained in 2016. As of June 30, 2016, the International Energy segment had a carrying value of approximately $2.4 billion , adjusted for approximately $589 million of cumulative foreign currency translation losses currently classified as accumulated other comprehensive loss. Midwest Generation Exit Duke Energy, through indirect subsidiaries, completed the sale of the Disposal Group to a subsidiary of Dynegy on April 2, 2015, for approximately $2.8 billion in cash. The nonregulated Midwest generation business included generation facilities with approximately 5,900 MW of owned capacity located in Ohio, Pennsylvania and Illinois. On April 1, 2015, prior to the sale, Duke Energy Ohio distributed its indirect ownership interest in the nonregulated Midwest generation business to a subsidiary of Duke Energy Corporation. The Disposal Group's results of operations are classified as discontinued operations in the accompanying Condensed Consolidated Statements of Operations and Comprehensive Income. The following table presents the results of discontinued operations for the three and six months ended June 30, 2015 . Three Months Ended Six Months Ended June 30, 2015 June 30, 2015 Duke Duke Duke Energy Duke Energy (in millions) Energy Ohio Energy Ohio Operating Revenues $ — $ — $ 543 $ 412 Gain (Loss) on disposition 6 — (37 ) (44 ) (Loss) Income before income taxes (a) $ (80 ) $ (88 ) $ 67 $ 52 Income tax (benefit) expense (21 ) (23 ) 30 27 (Loss) Income from discontinued operations of the Disposal Group (59 ) (65 ) 37 25 Other, net of tax (b) 2 — (3 ) — (Loss) Income from Discontinued Operations, net of tax $ (57 ) $ (65 ) $ 34 $ 25 (a) The (Loss) Income before income taxes includes the pretax impact of a $71 million and $81 million charge for the agreement in principle reached in a lawsuit related to the Disposal Group for the three and six months ended June 30, 2015, respectively. Refer to Note 5 for further information related to the lawsuit. (b) Relates to discontinued operations of businesses not related to the Disposal Group and includes indemnifications provided for certain legal, tax and environmental matters, and foreign currency translation adjustments. Commercial Portfolio utilized a revolving credit agreement (RCA) to support the operations of the nonregulated Midwest generation business. Interest expense associated with the RCA was allocated to discontinued operations. No other interest expense related to corporate level debt was allocated to discontinued operations. Duke Energy Ohio had a power purchase agreement with the Disposal Group for a portion of its standard service offer (SSO) supply requirement. The agreement and the SSO expired in May 2015.

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS Duke Energy evaluates segment performance based on segment income. Segment income is defined as income from continuing operations net of income attributable to noncontrolling interests. Segment income, as discussed below, includes intercompany revenues and expenses that are eliminated in the Condensed Consolidated Financial Statements. Certain governance costs are allocated to each segment. In addition, direct interest expense and income taxes are included in segment income. Operating segments are determined based on information used by the chief operating decision-maker in deciding how to allocate resources and evaluate the performance of the business. During the first quarter of 2016, the Duke Energy chief operating decision-maker began to evaluate interim period segment performance based on financial information that includes the impact of income tax levelization within segment income. This represents a change from the previous measure, where the interim period impacts of income tax levelization were included within Other, and therefore excluded from segment income. As a result, prior period segment results presented have been recast to conform to this change. Products and services are sold between affiliate companies and reportable segments of Duke Energy at cost. Segment assets as presented in the tables that follow exclude all intercompany assets. DUKE ENERGY Duke Energy has the following reportable operating segments: Regulated Utilities, International Energy and Commercial Portfolio. Regulated Utilities conducts electric and natural gas operations that are substantially all regulated and, accordingly, qualify for regulatory accounting treatment. These operations are primarily conducted through the Subsidiary Registrants and are subject to the rules and regulations of the FERC, NRC, NCUC, PSCSC, FPSC, PUCO, IURC and KPSC. International Energy operates and manages power generation facilities and engages in sales and marketing of electric power, natural gas and natural gas liquids outside the U.S. Its activities principally target power generation in Latin America. Additionally, International Energy owns a 25 percent interest in NMC, a large regional producer of methyl tertiary butyl ether (MTBE) located in Saudi Arabia. The investment in NMC is accounted for under the equity method of accounting. In February 2016, Duke Energy announced it had initiated a process to potentially divest its International Energy business segment, excluding the investment in NMC. See Note 2 for further information. Commercial Portfolio builds, develops and operates wind and solar renewable generation and storage and energy transmission projects throughout the U.S. For periods subsequent to the sale of the Disposal Group, beginning in the second quarter of 2015, certain immaterial results of operations and related assets previously presented in the Commercial Portfolio segment are presented in Regulated Utilities and Other. The remainder of Duke Energy’s operations is presented as Other, which is primarily comprised of unallocated corporate interest expense, unallocated corporate costs, contributions to the Duke Energy Foundation and the operations of Duke Energy’s wholly owned captive insurance subsidiary, Bison Insurance Company Limited (Bison). Three Months Ended June 30, 2016 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 5,090 $ 270 $ 112 $ 5,472 $ 12 $ — $ 5,484 Intersegment revenues 9 — — 9 17 (26 ) — Total revenues $ 5,099 $ 270 $ 112 $ 5,481 $ 29 $ (26 ) $ 5,484 Segment income (loss) (a)(b) $ 718 $ (102 ) $ 14 $ 630 $ (120 ) $ — $ 510 Add back noncontrolling interests 3 Loss from discontinued operations, net of tax (1 ) Net income $ 512 Segment assets $ 112,754 $ 3,131 $ 4,329 $ 120,214 $ 2,260 $ 180 $ 122,654 (a) Other includes after-tax charges for costs to achieve mergers of $69 million , primarily due to unrealized losses on forward-starting interest rate swaps related to the Piedmont acquisition, and cost savings initiatives of $15 million primarily due to severance costs. See Notes 2 and 9 for additional information related to the forward-starting interest rate swaps. (b) International Energy includes an after-tax impairment charge of $145 million . See Note 2 for additional information. Three Months Ended June 30, 2015 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 5,211 $ 287 $ 75 $ 5,573 $ 16 $ — $ 5,589 Intersegment revenues 9 — — 9 18 (27 ) — Total revenues $ 5,220 $ 287 $ 75 $ 5,582 $ 34 $ (27 ) $ 5,589 Segment income (loss) (a)(b) $ 632 $ 52 $ (30 ) $ 654 $ (51 ) $ (3 ) $ 600 Add back noncontrolling interests 4 Loss from discontinued operations, net of tax (c) (57 ) Net income $ 547 (a) Other includes after-tax costs to achieve the Progress Energy merger of $14 million . (b) Commercial Portfolio includes state tax expense of $41 million , resulting from changes to state apportionment factors due to the sale of the Disposal Group, that does not qualify for discontinued operations. Refer to Note 2 for further information related to the sale. (c) Includes the after-tax impact of $46 million for the agreement in principle reached in a lawsuit related to the Disposal Group. Refer to Note 5 for further information related to the lawsuit. Six Months Ended June 30, 2016 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 10,340 $ 516 $ 227 $ 11,083 $ 23 $ — $ 11,106 Intersegment revenues 18 — — 9 35 (53 ) — Total revenues $ 10,358 $ 516 $ 227 $ 11,092 $ 58 $ (53 ) $ 11,106 Segment income (loss) (a)(b) $ 1,413 $ 21 $ 41 $ 1,475 $ (274 ) $ — $ 1,201 Add back noncontrolling interests 8 Income from discontinued operations, net of tax 2 Net income $ 1,211 (a) Other includes after-tax charges for costs to achieve mergers of $143 million , primarily due to unrealized losses on forward-starting interest rate swaps related to the Piedmont acquisition, and cost savings initiatives of $27 million primarily due to severance costs. See Notes 2 and 9 for additional information related to the forward-starting interest rate swaps. (b) International Energy includes an after-tax impairment charge of $145 million . See Note 2 for additional information. Six Months Ended June 30, 2015 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 10,924 $ 560 $ 148 $ 11,632 $ 22 $ — $ 11,654 Intersegment revenues 19 — — 19 39 (58 ) — Total revenues $ 10,943 $ 560 $ 148 $ 11,651 $ 61 $ (58 ) $ 11,654 Segment income (loss) (a)(b) $ 1,406 $ 88 $ (23 ) $ 1,471 $ (94 ) $ (4 ) $ 1,373 Add back noncontrolling interests 7 Income from discontinued operations, net of tax (c) 34 Net income $ 1,414 (a) Other includes after-tax costs to achieve the Progress Energy merger of $27 million . (b) Commercial Portfolio includes state tax expense of $41 million , resulting from changes to state apportionment factors due to the sale of the Disposal Group, that does not qualify for discontinued operations. Refer to Note 2 for further information related to the sale. (c) Includes after-tax impact of $53 million for the agreement in principle reached in a lawsuit related to the Disposal Group. Refer to Note 5 for further information related to the lawsuit. SUBSIDIARY REGISTRANTS The Subsidiary Registrants each have one reportable operating segment, Regulated Utilities, which generates, transmits, distributes and sells electricity, and for Duke Energy Ohio, also transports and sells natural gas. The remainder of operations is primarily comprised of unallocated corporate costs and classified as Other. The following table provides the amount of Other net expense. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas $ (17 ) $ (10 ) $ (34 ) $ (18 ) Progress Energy (a) (45 ) (42 ) (94 ) (84 ) Duke Energy Progress (8 ) (4 ) (16 ) (8 ) Duke Energy Florida (5 ) (3 ) (9 ) (6 ) Duke Energy Ohio (10 ) (6 ) (19 ) (8 ) Duke Energy Indiana (5 ) (2 ) (7 ) (4 ) (a) Other for Progress Energy also includes interest expense on corporate debt instruments of $55 million and $111 million for the three and six months ended June 30, 2016 , respectively, and $59 million and $119 million for the three and six months ended June 30, 2015 , respectively. The assets of the Subsidiary Registrants are substantially all included within the Regulated Utilities segment at June 30, 2016 . Duke Energy Ohio Duke Energy Ohio had two reportable operating segments, Regulated Utilities and Commercial Portfolio, during 2015 prior to the sale of the nonregulated Midwest generation business. Duke Energy Ohio's Commercial Portfolio segment had total revenues of $14 million and segment loss of $9 million for the six months ended June 30, 2015. As a result of the sale discussed in Note 2 , Commercial Portfolio no longer qualifies as a Duke Energy Ohio reportable operating segment. Therefore, beginning in the second quarter of 2015, all of the remaining assets and related results of operations previously presented in Commercial Portfolio are presented in Regulated Utilities and Other.

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2016
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS RATE RELATED INFORMATION The NCUC, PSCSC, FPSC, IURC, PUCO and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio, Kentucky and Indiana), as well as sales of transmission service. Duke Energy Carolinas and Duke Energy Progress Ash Basin Closure Costs Deferral On July 13, 2016, in response to a joint petition of Duke Energy Carolinas and Duke Energy Progress the PSCSC issued an accounting order for the deferment into a regulatory account of certain costs incurred in connection with federal and state environmental remediation requirements related to the permanent closure of ash basins and other ash storage units at coal-fired generating facilities that have provided or are providing generation to customers located in South Carolina. The decision allows for ash basin closure expenses to be partially offset with excess regulatory liability amounts from the deferral of nuclear decommissioning costs that are collected from South Carolina retail customers and for Duke Energy Progress to offset incurred ash basin closure costs with costs of removal amounts collected from customers. The PSCSC's ruling does not change retail rates or the tariff amounts and in no way limits the PSCSC's ability to challenge the reasonableness of expenditures in subsequent proceedings. FERC Transmission Return on Equity Complaints On January 7, 2016, a group of transmission service customers filed a complaint with the FERC that the rate of return on equity of 10.2 percent in Duke Energy Carolinas' transmission formula rates is excessive and should be reduced to no higher than 8.49 percent , effective upon the complaint date. On the same date a similar complaint was filed with the FERC claiming that the rate of return on equity of 10.8 percent in Duke Energy Progress' transmission formula rates is excessive and should be reduced to no higher than 8.49 percent , effective upon the complaint date. On April 21, 2016, the FERC issued an order which consolidated the cases, set a refund effective date of January 7, 2016, and set the consolidated case for settlement and hearing. Duke Energy Carolinas and Duke Energy Progress do not expect the potential impact on results of operations, cash flows or financial position to be material. Duke Energy Carolinas Advanced Metering Infrastructure Deferral On July 12, 2016, the PSCSC issued an accounting order for Duke Energy Carolinas to defer the financial effects of depreciation expense incurred for the installation of advanced metering infrastructure (AMI) meters, the carrying costs on the investment at its weighted average cost of capital and the carrying costs on the deferred costs at its weighted average cost of capital not to exceed $45 million . The decision also allows Duke Energy Carolinas to continue to depreciate the non-AMI meters to be replaced. Current retail rates will not change as a result of the decision and the PSCSC's ability to challenge the reasonableness of expenditures in subsequent proceedings is not limited. William States Lee Combined Cycle Facility On April 9, 2014, the PSCSC granted Duke Energy Carolinas and North Carolina Electric Membership Corporation (NCEMC) a Certificate of Environmental Compatibility and Public Convenience and Necessity (CECPCN) for the construction and operation of a 750 MW combined-cycle natural gas-fired generating plant at Duke Energy Carolinas' existing William States Lee Generating Station in Anderson, South Carolina. Duke Energy Carolinas began construction in July 2015 and estimates a cost to build of $600 million for its share of the facility, including allowance for funds used during construction (AFUDC). The project is expected to be commercially available in late 2017. NCEMC will own approximately 13 percent of the project. On July 3, 2014, the South Carolina Coastal Conservation League (SCCL) and Southern Alliance for Clean Energy (SACE) jointly filed a Notice of Appeal with the Court of Appeals of South Carolina (S.C. Court of Appeals) seeking the court's review of the PSCSC's decision, claiming the PSCSC did not properly consider a request related to a proposed solar facility prior to granting approval of the CECPCN. The S.C. Court of Appeals affirmed the PSCSC's decision on February 10, 2016, and on March 24, 2016, denied a request for rehearing filed by SCCL and SACE. On April 21, 2016, SCCL and SACE petitioned the South Carolina Supreme Court for review of the S.C. Court of Appeals decision. Duke Energy Carolinas filed its response on June 13, 2016, and SCCL and SACE filed a reply on June 23, 2016. Duke Energy Carolinas cannot predict the outcome of this matter. Duke Energy Progress South Carolina Rate Case On July 1, 2016, Duke Energy Progress filed an application with the PSCSC requesting an average 14.5 percent increase in retail revenues. The requested rate change would increase annual revenues by approximately $79 million , with a rate of return on equity of 10.75 percent . The increase is designed to recover the cost of investment in new generation infrastructure, environmental expenditures including allocated historical ash basin closure costs and increased nuclear operating costs. Duke Energy Progress has requested new rates to be effective January 1, 2017. A hearing has been scheduled to begin on October 31, 2016. Duke Energy Progress cannot predict the outcome of this matter. Western Carolinas Modernization Plan On November 4, 2015, in response to community feedback, Duke Energy Progress announced a revised Western Carolinas Modernization Plan with an estimated cost of $1.1 billion . The revised plan includes retirement of the existing Asheville coal-fired plant, the construction of two 280 MW combined-cycle natural gas plants having dual fuel capability, with the option to build a third natural gas simple cycle unit in 2023 based upon the outcome of initiatives to reduce the region's power demand. The revised plan includes upgrades to existing transmission lines and substations, but eliminates the need for a new transmission line and a new substation associated with the project in South Carolina. The revised plan has the same overall project cost as the original plan and the plans to install solar generation remain unchanged. Duke Energy Progress has also proposed to add a pilot battery storage project. These investments will be made within the next seven years. Duke Energy Progress is also working with the local natural gas distribution company to upgrade an existing natural gas pipeline to serve the natural gas plant. The plan requires various approvals including regulatory approvals in North Carolina. Duke Energy Progress filed for a Certificate of Public Convenience and Necessity (CPCN) with the NCUC for the new natural gas units on January 15, 2016. On March 28, 2016, the NCUC issued an order approving the CPCN for the new combined-cycle natural gas plants, but denying the CPCN for the contingent simple cycle unit without prejudice to Duke Energy Progress to refile for approval in the future. Construction of these plants is scheduled to begin in 2016 and the plants are expected to be in service by late 2019. Duke Energy Progress plans to file for future approvals related to the proposed solar generation and pilot battery storage project. On May 27, 2016, NC WARN and The Climate Times filed a notice of appeal from the CPCN order to the N.C. Court of Appeals. On May 31, 2016, Duke Energy Progress filed a motion to dismiss the notice of appeal with the NCUC due to NC WARN's and The Climate Times' failure to post a required appeal bond. After a series of filings, an NCUC order, petitions to the N.C. Court of Appeals and an evidentiary hearing, on July 8, 2016, the NCUC issued an order setting NC WARN's and The Climate Times' appeal bond at $98 million . On July 28, 2016, NC WARN and The Climate Times filed a notice of appeal and exceptions from the NCUC's July 8, 2016, appeal bond order. On August 2, 2016, the NCUC granted Duke Energy Progress' motion to dismiss NC WARN's and The Climate Times' notice of appeal from the CPCN order due to failure to post the requisite bond. Duke Energy Progress cannot predict the outcome of this matter. The carrying value of the 376 MW Asheville coal-fired plant, including associated ash basin closure costs, of $506 million and $548 million are included in Generation facilities to be retired, net on Duke Energy Progress' Condensed Consolidated Balance Sheet as of June 30, 2016 and December 31, 2015 , respectively. Duke Energy Florida Hines Chiller Uprate Project On May 20, 2016, Duke Energy Florida filed a petition seeking approval to include in base rates the revenue requirement for a Chiller Uprate Project (Uprate Project) at the Hines station. Duke Energy Florida proposes to complete the Uprate Project in two phases: phase one work on Hines Units 1-3 and the common equipment to be completed and placed into service in October 2016; and phase two work on Hines Unit 4 to be completed and placed into service in January 2017. The final construction cost estimate for both phases of approximately $150 million is below the cost estimate provided during the need determination proceeding. Duke Energy Florida estimates the annual retail revenue requirements for phases one and two to be approximately $16 million and $3 million , respectively. Duke Energy Florida’s petition seeks approval of both revenue requirements, but only seeks to include the phase one revenue requirement in base rates and customer bills beginning November 2016, and will separately petition to include the phase two revenue requirement in base rates and customer bills beginning February 2017. Duke Energy Florida cannot predict the outcome of this matter. Purchase of Osprey Energy Center In December 2014, Duke Energy Florida and Osprey Energy Center, LLC, a wholly owned subsidiary of Calpine Corporation (Calpine), entered into an Asset Purchase and Sale Agreement for the purchase of a 599 MW combined-cycle natural gas plant in Auburndale, Florida (Osprey Plant acquisition) for approximately $166 million . In July 2015, the FERC and the FPSC issued separate orders of approval for the Osprey Plant acquisition. The Hart-Scott-Rodino waiting period expired on May 2, 2016. Closing of the acquisition is expected to occur by the first quarter of 2017, upon the expiration of an existing Power Purchase Agreement between Calpine and Duke Energy Florida. In anticipation of closing, in August 2016, Duke Energy Florida filed a petition seeking approval to include in base rates the revenue requirements for the Osprey Plant acquisition to be included in customer bills beginning in February 2017. Duke Energy Florida estimates the retail revenue requirements to be approximately $48 million . Crystal River Unit 3 Regulatory Asset In June 2015, the governor of Florida signed legislation to allow utilities to issue nuclear asset-recovery bonds to finance the recovery of certain retired nuclear generation assets, with approval of the FPSC. In November 2015, the FPSC issued a financing order approving Duke Energy Florida’s request to issue nuclear asset-recovery bonds to finance its unrecovered regulatory asset related to Crystal River Unit 3 (Crystal River 3) through a wholly owned special purpose entity. Nuclear asset-recovery bonds replace the base rate recovery methodology authorized by the 2013 Revised and Restated Stipulation and Settlement Agreement (2013 Agreement) and result in a lower rate impact to customers with a recovery period of approximately 20 years . Pursuant to provisions in Florida Statutes and the FPSC financing order, in 2016, Duke Energy Florida formed Duke Energy Florida Project Finance, LLC (DEFPF), a wholly owned, bankruptcy remote special purpose subsidiary for the purpose of issuing nuclear asset-recovery bonds. In June 2016, DEFPF issued $1,294 million aggregate principal amount of senior secured bonds (nuclear asset-recovery bonds) to finance the recovery of Duke Energy Florida's Crystal River 3 regulatory asset. In connection with this financing, net proceeds to DEFPF of approximately $1,287 million , after underwriting costs, were used to acquire nuclear asset-recovery property from Duke Energy Florida and to pay transaction related expenses. The nuclear asset-recovery property includes the right to impose, bill, collect and adjust a non-bypassable nuclear asset-recovery charge, to be collected on a per kilowatt-hour basis from all Duke Energy Florida retail customers until the bonds are paid in full. Duke Energy Florida began collecting the nuclear asset-recovery charge on behalf of DEFPF in customer rates in July 2016. See Notes 6 and 12 for additional information. Duke Energy Ohio Natural Gas Pipeline Extension Duke Energy Ohio is proposing to install a new natural gas pipeline in its Ohio service territory to increase system reliability and enable the retirement of older infrastructure. The proposed project involves the installation of a natural gas line and is estimated to cost between $100 million and $150 million . Duke Energy Ohio is currently evaluating potential routes and has conducted public informational meetings. Duke Energy Ohio will narrow the route options to two and then make a filing with the Ohio Power Siting Board for approval of one of the two proposed routes. Advanced Metering Infrastructure On April 25, 2016, Duke Energy Kentucky filed with the KPSC an application for approval of a certificate of public convenience and necessity for the construction of advanced metering infrastructure. Duke Energy Kentucky anticipates that the estimated $49 million project, if approved, will take about two years to complete. Duke Energy Kentucky also requested approval to establish a regulatory asset of approximately $10 million for the remaining book value of existing meter equipment and inventory that will be replaced. On July 20, 2016, the Kentucky Attorney General, the only intervenor in the proceeding, moved to dismiss the application. Duke Energy Kentucky filed its opposition to the Kentucky Attorney General's motion to dismiss on July 27, 2016. Duke Energy Kentucky cannot predict the outcome of this matter. Accelerated Natural Gas Service Line Replacement Rider On January 20, 2015, Duke Energy Ohio filed an application for approval of an accelerated natural gas service line replacement program (ASRP). Under the ASRP, Duke Energy Ohio proposes to replace certain natural gas service lines on an accelerated basis. The program is proposed to last 10 years. Through the ASRP, Duke Energy Ohio also proposes to complete preliminary survey and investigation work related to natural gas service lines that are customer owned and for which it does not have valid records and, further, to relocate interior natural gas meters to suitable exterior locations where such relocation can be accomplished. Duke Energy Ohio projects total capital and operations and maintenance expenditures under the ASRP to approximate $320 million . The filing also seeks approval of Rider ASRP to recover related expenditures. Duke Energy Ohio proposes to update Rider ASRP on an annual basis. Duke Energy Ohio’s application is pending before the PUCO and it is uncertain when an order will be issued. Intervenors oppose the ASRP, primarily because they believe the program is neither required nor necessary under federal pipeline regulation. The hearing concluded on November 19, 2015, and initial and reply briefs were filed, with briefing complete on December 23, 2015. Duke Energy Ohio cannot predict the outcome of this matter. Energy Efficiency Cost Recovery On March 28, 2014, Duke Energy Ohio filed an application for recovery of program costs, lost distribution revenue and performance incentives related to its energy efficiency and peak demand reduction programs. These programs are undertaken to comply with environmental mandates set forth in Ohio law. After a comment period, the PUCO approved Duke Energy Ohio’s application, but found that Duke Energy Ohio was not permitted to use banked energy savings from previous years in order to calculate the amount of allowed incentive. This conclusion represented a change to the cost recovery mechanism that had been agreed to by intervenors and approved by the PUCO in previous cases. The PUCO granted the applications for rehearing filed by Duke Energy Ohio and an intervenor on July 8, 2015. Substantive ruling on the application for rehearing is pending. On January 6, 2016, Duke Energy Ohio and PUCO Staff entered into a stipulation pending PUCO approval, resolving the issues related to, among other things, performance incentives and the PUCO Staff audit of 2013 costs. Based on the stipulation, in December 2015, Duke Energy Ohio re-established approximately $20 million of revenues that had been reversed in the second quarter of 2015. A hearing on the stipulation commenced on March 10, 2016, and the post-hearing briefing has concluded. Duke Energy Ohio cannot predict the outcome of this matter. 2012 Natural Gas Rate Case/Manufactured Gas Plant Cost Recovery On November 13, 2013, the PUCO issued an order approving a settlement of Duke Energy Ohio’s natural gas base rate case and authorizing the recovery of costs incurred between 2008 and 2012 for environmental investigation and remediation of two former manufactured gas plant (MGP) sites. The order contained deadlines for the recovery of such costs. Specifically, for the property known as the East End site, PUCO established a deadline of December 31, 2016, and for the West End site, a deadline of December 31, 2019. The PUCO authorized Duke Energy Ohio to seek to extend these deadlines due to certain circumstances. On May 16, 2016, Duke Energy Ohio filed an application to extend the deadline for cost recovery applicable to the East End site. The order also authorized Duke Energy Ohio to continue deferring environmental investigation and remediation costs incurred subsequent to 2012 and to submit annual filings to adjust the MGP rider for future costs. Duke Energy Ohio submitted MGP rider update filings in 2014, 2015, and 2016 for recovery of costs incurred in 2013, 2014, and 2015, which are pending approval. Duke Energy Ohio cannot predict the outcome of this matter. Regional Transmission Organization Realignment Duke Energy Ohio, including Duke Energy Kentucky, transferred control of its transmission assets from Midcontinent Independent System Operator, Inc. (MISO) to PJM Interconnection, LLC (PJM), effective December 31, 2011. The PUCO approved a settlement related to Duke Energy Ohio’s recovery of certain costs of the Regional Transmission Organization (RTO) realignment via a non-bypassable rider. Duke Energy Ohio is allowed to recover all MISO Transmission Expansion Planning (MTEP) costs, including but not limited to Multi Value Project (MVP) costs, directly or indirectly charged to Ohio customers. Duke Energy Ohio also agreed to vigorously defend against any charges for MVP projects from MISO. The KPSC also approved a request to effect the RTO realignment, subject to a commitment not to seek double recovery in a future rate case of the transmission expansion fees that may be charged by MISO and PJM in the same period or overlapping periods. Duke Energy Ohio had a recorded liability for its exit obligation and share of MTEP costs, excluding MVP, of $91 million and $92 million , respectively, at June 30, 2016 and December 31, 2015 , within Other in Current liabilities and Other in Deferred credits and other liabilities on Duke Energy Ohio’s Condensed Consolidated Balance Sheets. The retail portion of MTEP costs billed by MISO are recovered by Duke Energy Ohio through a non-bypassable rider. As of June 30, 2016 and December 31, 2015, Duke Energy Ohio had $72 million recorded in Regulatory assets on the Condensed Consolidated Balance Sheets. MVP. MISO approved 17 MVP proposals prior to Duke Energy Ohio’s exit from MISO on December 31, 2011. Construction of these projects is expected to continue through 2020. Costs of these projects, including operating and maintenance costs, property and income taxes, depreciation and an allowed return, are allocated and billed to MISO transmission owners. On December 29, 2011, MISO filed a tariff with the FERC providing for the allocation of MVP costs to a withdrawing owner based on monthly energy usage. The FERC set for hearing (i) whether MISO’s proposed cost allocation methodology to transmission owners who withdrew from MISO prior to January 1, 2012, is consistent with the tariff at the time of their withdrawal from MISO and, (ii) if not, what the amount of and methodology for calculating any MVP cost responsibility should be. In 2012, MISO estimated Duke Energy Ohio’s MVP obligation over the period from 2012 to 2071 at $2.7 billion , on an undiscounted basis. On July 16, 2013, a FERC Administrative Law Judge (ALJ) issued an initial decision. Under this initial decision, Duke Energy Ohio would be liable for MVP costs. Duke Energy Ohio filed exceptions to the initial decision, requesting FERC to overturn the ALJ’s decision. On October 29, 2015, the FERC issued an order reversing the ALJ's decision. The FERC ruled the cost allocation methodology is not consistent with the MISO tariff and that Duke Energy Ohio has no liability for MVP costs after its withdrawal from MISO. On May 19, 2016, the FERC denied the request for rehearing filed by MISO and the MISO Transmission Owners. On July 15, 2016, the MISO Transmission Owners filed a petition for review with the U.S. Court of Appeals for the Sixth Circuit. Duke Energy Ohio cannot predict the outcome of this matter. Duke Energy Indiana Coal Combustion Residual Plan On March 17, 2016, Duke Energy Indiana filed with the IURC a request for approval of its first group of federally mandated Coal Combustion Residual (CCR) rule compliance projects (Phase I CCR Compliance Projects) to comply with the U.S. Environmental Protection Agency's (EPA) CCR rule. The projects in this Phase I filing are CCR compliance projects, including the conversion of Cayuga and Gibson Stations to dry bottom ash handling and related water treatment. Duke Energy Indiana has requested timely recovery of approximately $380 million in retail capital costs and incremental operating and maintenance costs under a federal mandate tracker which provides for timely recovery of 80 percent of such costs and deferral with carrying costs of 20 percent of such costs for recovery in a subsequent retail base rate case. An evidentiary hearing is scheduled for November 2016. Duke Energy Indiana cannot predict the outcome of this matter. Edwardsport Integrated Gasification Combined Cycle Plant On November 20, 2007, the IURC granted Duke Energy Indiana a CPCN for the construction of the Edwardsport Integrated Gasification Combined Cycle (IGCC) Plant. The Citizens Action Coalition of Indiana, Inc., Sierra Club, Inc., Save the Valley, Inc., and Valley Watch, Inc. (collectively, the Joint Intervenors) were intervenors in several matters related to the Edwardsport IGCC Plant. The Edwardsport IGCC Plant was placed in commercial operation in June 2013. Costs for the Edwardsport IGCC Plant are recovered from retail electric customers via a tracking mechanism, the IGCC rider. The ninth semi-annual IGCC rider order was appealed by the Joint Intervenors. The proceeding has been remanded to the IURC for further proceedings and additional findings on the tax in-service issue. An evidentiary hearing has been set for September 13, 2016. The 11th through 15th semi-annual IGCC riders and a subdocket to Duke Energy Indiana's fuel adjustment clause remain pending at the IURC. Issues in these filings include the determination whether the IGCC plant was properly declared in-service for ratemaking purposes in June 2013 and a review of the operational performance of the plant. On September 17, 2015, Duke Energy Indiana, the Office of Utility Consumer Counselor, the Industrial Group and Nucor Steel Indiana reached a settlement agreement to resolve these pending issues. On January 15, 2016, The Citizens Action Coalition of Indiana, Inc., Sierra Club, Save the Valley and Valley Watch joined a revised settlement (IGCC settlement). The IGCC settlement will result in customers not being billed for previously incurred operating costs of $87.5 million , and for additional Duke Energy Indiana payments and commitments of $5.5 million for attorneys’ fees and amounts to fund consumer programs. Attorneys’ fees and expenses for the new settling parties will be addressed in a separate proceeding. Duke Energy Indiana recognized pretax impairment and related charges of $93 million in 2015. Additionally, under the IGCC settlement, the operating and maintenance expenses and ongoing maintenance capital at the plant are subject to certain caps during the years of 2016 and 2017. The IGCC settlement also includes a commitment to either retire or stop burning coal by December 31, 2022, at the Gallagher Station. Pursuant to the IGCC settlement, the in-service date used for accounting and ratemaking will remain as June 2013. Remaining deferred costs will be recovered over eight years and not earn a carrying cost. The IGCC settlement, which is opposed by an intervenor, is subject to IURC approval. An evidentiary hearing on the IGCC settlement was held on April 18, 2016, and a decision is expected in the third quarter of 2016. As of June 30, 2016 , deferred costs related to the project are approximately $175 million . Under the IGCC settlement, future IGCC riders will be filed annually, rather than every six months, with the next filing scheduled for first quarter 2017. Duke Energy Indiana cannot predict the outcome of these matters or future IGCC rider proceedings. FERC Transmission Return on Equity Complaint Customer groups have filed with the FERC complaints against MISO and its transmission-owning members, including Duke Energy Indiana, alleging, among other things, that the current base rate of return on equity earned by MISO transmission owners of 12.38 percent is unjust and unreasonable. The latest complaint, filed on February 12, 2015, claims the base rate of return on equity should be reduced to 8.67 percent and requests a consolidation of complaints. The motion to consolidate complaints was denied. On January 5, 2015, the FERC issued an order accepting the MISO transmission owners 0.50 percent adder to the base rate of return on equity based on participation in an RTO subject to it being applied to a return on equity that is shown to be just and reasonable in the pending return on equity complaints. A hearing in the base return on equity proceeding was held in August 2015. On December 22, 2015, the presiding FERC ALJ in the first complaint issued an Initial Decision in which he set the base rate of return on equity at 10.32 percent . On June 30, 2016, the presiding FERC ALJ in the second complaint issued an Initial Decision setting the base rate of return on equity at 9.70 percent . The Initial Decisions will be reviewed by the FERC. Duke Energy Indiana currently believes these matters will have an immaterial impact on its results of operations, cash flows and financial position. Grid Infrastructure Improvement Plan On August 29, 2014, pursuant to a new statute, Duke Energy Indiana filed a seven-year grid infrastructure improvement plan with the IURC with an estimated cost of $1.9 billion , focusing on the reliability, integrity and modernization of the transmission and distribution system. The plan also provided for cost recovery through a transmission and distribution rider (T&D Rider). In May 2015, the IURC denied the original proposal due to an insufficient level of detailed projects and cost estimates in the plan. On December 7, 2015, Duke Energy Indiana filed a revised infrastructure improvement plan with an estimated cost of $1.8 billion in response to guidance from IURC orders and the Indiana Court of Appeals decisions related to this new statute. The revised plan uses a combination of advanced technology and infrastructure upgrades to improve service to customers and provide them with better information about their energy use. It also provides for cost recovery through a T&D rider. In March 2016, Duke Energy Indiana entered into a settlement with all parties to the proceeding except the Citizens Action Coalition of Indiana, Inc. The settlement agreement decreased the capital expenditures eligible for timely recovery of costs in the seven-year plan to approximately $1.4 billion , including the removal of an AMI project. The settlement provided for deferral accounting for depreciation and post-in-service carrying costs for AMI projects outside the seven-year plan. Duke Energy Indiana withdrew its request for a regulatory asset for current meters and will retain any savings associated with future AMI installation until the next retail base rate case, which is required to be filed prior to the end of the seven-year plan. Under the settlement, the return on equity to be used in the T&D Rider is 10 percent . The IURC approved the settlement and issued a final order on June 29, 2016. OTHER REGULATORY MATTERS Atlantic Coast Pipeline On September 2, 2014, Duke Energy, Dominion Resources (Dominion), Piedmont and AGL Resources announced the formation of a company, ACP, to build and own the proposed Atlantic Coast Pipeline (the pipeline), a 564-mile interstate natural gas pipeline. The pipeline is designed to meet the needs identified in requests for proposals by Duke Energy Carolinas, Duke Energy Progress and Piedmont. Dominion will build and operate the pipeline and has a 45 percent ownership percentage in ACP. Duke Energy has a 40 percent ownership interest in ACP through its Commercial Portfolio segment. Piedmont owns 10 percent and the remaining share is owned by AGL Resources. Duke Energy Carolinas and Duke Energy Progress, among others, will be customers of the pipeline. Purchases will be made under several 20-year supply contracts, subject to state regulatory approval. In October 2014, the NCUC and PSCSC approved the Duke Energy Carolinas and Duke Energy Progress requests to enter into certain affiliate agreements, pay compensation to ACP and to grant a waiver of certain Code of Conduct provisions relating to contractual and jurisdictional matters. On September 18, 2015, ACP filed an application with the FERC requesting a CPCN authorizing ACP to construct the pipeline. FERC approval of the application is expected in early 2017 and construction is projected to begin in summer of 2017, with a targeted in-service date of late 2018. ACP is working with various agencies to develop the final pipeline route. ACP also requested approval of an open access tariff and the precedent agreements it entered into with future pipeline customers, including Duke Energy Carolinas and Duke Energy Progress. On October 24, 2015, Duke Energy entered into a Merger Agreement with Piedmont. The ACP partnership agreement includes provisions to allow Dominion an option to purchase additional ownership interest in ACP to maintain a leading ownership percentage. Any change in ownership interests is not expected to be material to Duke Energy. Refer to Note 2 for further information related to Duke Energy's proposed acquisition of Piedmont. Sabal Trail Transmission, LLC Pipeline On May 4, 2015, Duke Energy acquired a 7.5 percent ownership interest from Spectra Energy in the proposed 500-mile Sabal Trail natural gas pipeline. Spectra Energy will continue to own 59.5 percent of the Sabal Trail pipeline and NextEra Energy will own the remaining 33 percent . The Sabal Trail pipeline will traverse Alabama, Georgia and Florida to meet rapidly growing demand for natural gas in those states. The primary customers of the Sabal Trail pipeline, Duke Energy Florida and Florida Power & Light Company (FP&L), have each contracted to buy pipeline capacity for 25-year initial terms. On February 3, 2016, the FERC issued an order granting the request for a CPCN to construct and operate the Sabal Trail pipeline. The Sabal Trail pipeline requires additional regulatory approvals and is scheduled to begin service in mid-2017. Progress Energy Merger FERC Mitigation In June 2012, the FERC approved the merger with Progress Energy, including Duke Energy and Progress Energy’s revised market power mitigation plan, the Joint Dispatch Agreement (JDA) and the joint Open Access Transmission Tariff. The revised market power mitigation plan provided for the acceleration of one transmission proje

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES ENVIRONMENTAL Duke Energy is subject to international, federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. The Subsidiary Registrants are subject to federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. These regulations can be changed from time to time, imposing new obligations on the Duke Energy Registrants. Remediation Activities In addition to Asset Retirement Obligations recorded as a result of various environmental regulations, the Duke Energy Registrants are responsible for environmental remediation at various sites. These include certain properties that are part of ongoing operations and sites formerly owned or used by Duke Energy entities. These sites are in various stages of investigation, remediation and monitoring. Managed in conjunction with relevant federal, state and local agencies, remediation activities vary based upon site conditions and location, remediation requirements, complexity and sharing of responsibility. If remediation activities involve joint and several liability provisions, strict liability or cost recovery or contribution actions, the Duke Energy Registrants could potentially be held responsible for environmental impacts caused by other potentially responsible parties, and may also benefit from insurance policies or contractual indemnities that cover some or all cleanup costs. Liabilities are recorded when losses become probable and are reasonably estimable. The total costs that may be incurred cannot be estimated because the extent of environmental impact, allocation among potentially responsible parties, remediation alternatives and/or regulatory decisions have not yet been determined. Additional costs associated with remediation activities are likely to be incurred in the future and could be significant. Costs are typically expensed as Operation, maintenance and other in the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable. The following tables contain information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Other within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheets. Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Balance at beginning of period $ 97 $ 10 $ 17 $ 3 $ 14 $ 54 $ 12 Provisions/adjustments 28 3 4 1 3 1 21 Cash reductions (7 ) (2 ) (4 ) (1 ) (3 ) (1 ) (1 ) Balance at end of period $ 118 $ 11 $ 17 $ 3 $ 14 $ 54 $ 32 Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Balance at beginning of period $ 97 $ 10 $ 17 $ 5 $ 12 $ 54 $ 10 Provisions/adjustments 5 — 2 — 2 1 3 Cash reductions (4 ) — (2 ) (1 ) (1 ) (1 ) (1 ) Balance at end of period $ 98 $ 10 $ 17 $ 4 $ 13 $ 54 $ 12 Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below. (in millions) Duke Energy $ 75 Duke Energy Carolinas 22 Duke Energy Ohio 42 Duke Energy Indiana 7 North Carolina and South Carolina Ash Basins On February 2, 2014, a break in a stormwater pipe beneath an ash basin at Duke Energy Carolinas’ retired Dan River Steam Station caused a release of ash basin water and ash into the Dan River. On February 8, 2014, a permanent plug was installed in the stormwater pipe, stopping the release of materials into the river. Duke Energy Carolinas estimates 30,000 to 39,000 tons of ash and 24 million to 27 million gallons of basin water were released into the river. In July 2014, Duke Energy completed remediation work identified by the EPA and continues to cooperate with the EPA's civil enforcement process. Future costs related to the Dan River release, including pending or future state or federal civil enforcement proceedings, future regulatory directives, natural resources damages, additional pending litigation, future claims or litigation and long-term environmental impact costs, cannot be reasonably estimated at this time. North Carolina Department of Environmental Quality (NCDEQ), formerly the North Carolina Department of Environment and Natural Resources, has historically assessed Duke Energy Carolinas and Duke Energy Progress with Notice of Violations (NOV) for violations that were most often resolved through satisfactory corrective actions and minor, if any, fines or penalties. Subsequent to the Dan River matter discussed above, Duke Energy Carolinas and Duke Energy Progress have been served with a higher level of Notices of Violation (NOVs), including for violations at L.V. Sutton Plant and Dan River Steam Station. In August 2014, NCDEQ issued an NOV for alleged groundwater violations at Duke Energy Progress' L.V. Sutton Plant. On March 10, 2015, NCDEQ issued a civil penalty of approximately $25 million to Duke Energy Progress for environmental damages related to groundwater contamination at the L.V. Sutton Plant. On February 8, 2016, NCDEQ assessed a penalty of approximately $6.8 million , including enforcement costs, against Duke Energy Carolinas related to stormwater pipes and associated discharges at the Dan River Steam Station. Duke Energy Carolinas recorded a charge in December 2015 for this penalty. See "Litigation" section below for additional discussion of matters related to these penalties. These fines and penalties are unprecedented and were not consistent with historic enforcement practices of NCDEQ. Based on historic practices the expected liability of any existing notice of violations would not be material. Duke Energy Carolinas and Duke Energy Progress cannot predict whether the NCDEQ will assess future penalties related to existing NOVs and if such penalties would be material. Asset retirement obligations recorded on the Duke Energy Carolinas and Duke Energy Progress Condensed Consolidated Balance Sheets at June 30, 2016 and December 31, 2015 , include the legal obligation for closure of coal ash basins and the disposal of related ash as a result of the North Carolina Coal Ash Management Act of 2014, as amended (Coal Ash Act), and other agreements. In January 2016, NCDEQ published draft proposed risk classifications for sites not specifically delineated by the Coal Ash Act as high priority. These risk rankings were generally determined based on three primary criteria: structural integrity of the impoundments and impact to both surface and groundwater. NCDEQ categorized 12 basins at four sites as intermediate risk and four basins at 3 plants as low risk. Basins at high priority sites (Dan River, Riverbend, Asheville and Sutton) require closure through excavation including a combination of transferring the ash to an appropriate engineered landfill or conversion of the ash for beneficial use. Closure of high priority basins is required to be completed no later than August 1, 2019, except for Asheville which is required to be completed no later than August 1, 2022. Intermediate risk basins require closure through excavation including a combination of converting the basin to a lined industrial landfill, transferring of the ash to an appropriate engineered landfill or conversion of the ash for beneficial use. Closure of intermediate risk basins is required to be completed no later than December 31, 2024. Low risk basins require closure through either the combination of the installation and maintenance of a cap system and groundwater monitoring system designed to minimize infiltration and erosion or other closure options available to intermediate-risk basins. Closure of low risk basins is required to be completed no later than December 31, 2029. NCDEQ also categorized nine basins at six plants as “low-to-intermediate” risk, thereby not assigning a definitive risk ranking at that time. On May 18, 2016, NCDEQ issued new proposed risk classifications, ranking all originally proposed low risk and "low-intermediate" risk sites as intermediate. On July 14, 2016, the Governor of North Carolina signed legislation which amends the Coal Ash Act and requires Duke Energy to undertake dam improvement projects and to provide access to a permanent alternative drinking water source to certain residents within a half mile of coal ash basin compliance boundaries and to certain other potentially impacted residents. The new legislation also ranks basins at the H.F. Lee, Cape Fear and Weatherspoon stations as intermediate risk consistent with Duke Energy's previously announced plans to excavate those basins. These specific intermediate basins require closure through excavation including a combination of transferring ash to an appropriate engineered landfill or conversion of the ash for beneficial use. Closure of these specific intermediate basins is required to be completed no later than August 1, 2028. Additionally, the new legislation requires the installation and operation of three large-scale coal ash beneficiation projects which are expected to produce reprocessed ash for use in the concrete industry. Closure of basins at sites with these beneficiation projects are required to be completed no later than December 31, 2029 . Upon satisfactory completion of the dam improvement projects and installation of alternate drinking water sources by October 15, 2018, the legislation requires NCDEQ to reclassify intermediate risk sites, excluding H.F. Lee, Cape Fear and Weatherspoon, as low risk. Per the Coal Ash Act, final proposed classifications were to be subject to Coal Ash Management Commission (Coal Ash Commission) approval. In March 2016, the Coal Ash Commission created by the Coal Ash Act was disbanded by the Governor of North Carolina based on a North Carolina Supreme Court ruling regarding the constitutionality of the body. The new legislation eliminates the Coal Ash Commission and transfers responsibility for ash basin closure oversight to the NCDEQ. Estimated asset retirement obligations, including impacts from the legislation signed by the Governor of North Carolina on July 14, 2016, have been recognized based on the assigned risk categories or a probability weighting of potential closure methods. Actual closure costs incurred could be materially different from current estimates that form the basis of the recorded asset retirement obligations. Costs incurred have been deferred as regulatory assets and recovery will be pursued through the normal ratemaking process with federal and state utility commissions, which permit recovery of necessary and prudently incurred costs associated with Duke Energy’s regulated operations. Coal Combustion Residuals On April 17, 2015, the EPA published in the Federal Register a rule to regulate the disposal of CCR from electric utilities as solid waste. The federal regulation, which became effective in October 2015, classifies CCR as nonhazardous waste under Subtitle D of the Resource Conservation and Recovery Act and allows for beneficial use of CCR with some restrictions. The regulation applies to all new and existing landfills, new and existing surface impoundments receiving CCR and existing surface impoundments that are no longer receiving CCR but contain liquid located at stations currently generating electricity (regardless of fuel source). The rule establishes requirements regarding landfill design, structural integrity design and assessment criteria for surface impoundments, groundwater monitoring and protection procedures and other operational and reporting procedures to ensure the safe disposal and management of CCR. Various industry and environmental parties have appealed the EPA's CCR rule in the D.C. Circuit Court of Appeals. On April 18, 2016, the EPA filed an unopposed motion with the federal court to settle five issues raised in litigation. On June 14, 2016, the court approved the motion with respect to all of those issues. Duke Energy does not expect a material impact from the settlement or that it will result in additional asset retirement obligation adjustments. In addition to the requirements of the federal CCR regulation, CCR landfills and surface impoundments will continue to be independently regulated by most states. As a result of the EPA rule, the Subsidiary Registrants recorded asset retirement obligation amounts during 2015. LITIGATION Duke Energy Ash Basin Shareholder Derivative Litigation Five shareholder derivative lawsuits were filed in Delaware Chancery Court relating to the release at Dan River and to the management of Duke Energy’s ash basins. On October 31, 2014, the five lawsuits were consolidated in a single proceeding titled In Re Duke Energy Corporation Coal Ash Derivative Litigation . On December 2, 2014, plaintiffs filed a Corrected Verified Consolidated Shareholder Derivative Complaint (Consolidated Complaint). The Consolidated Complaint names as defendants several current and former Duke Energy officers and directors (Duke Energy Defendants). Duke Energy is named as a nominal defendant. The Consolidated Complaint alleges the Duke Energy Defendants breached their fiduciary duties by failing to adequately oversee Duke Energy’s ash basins and that these breaches of fiduciary duty may have contributed to the incident at Dan River and continued thereafter. The lawsuit also asserts claims against the Duke Energy Defendants for corporate waste (relating to the money Duke Energy has spent and will spend as a result of the fines, penalties and coal ash removal) and unjust enrichment (relating to the compensation and director remuneration that was received despite these alleged breaches of fiduciary duty). The lawsuit seeks both injunctive relief against Duke Energy and restitution from the Duke Energy Defendants. On January 21, 2015, the Duke Energy Defendants filed a Motion to Stay and an alternative Motion to Dismiss. On August 31, 2015, the court issued an order staying the case which was lifted on March 24, 2016. On April 22, 2016, plaintiffs filed an Amended Verified Consolidated Shareholder Derivative Complaint (Amended Complaint) making the same allegations as in the Consolidated Complaint. The Duke Energy Defendants filed a motion to dismiss the Amended Complaint on June 21, 2016. On March 5, 2015, shareholder Judy Mesirov filed a shareholder derivative complaint (Mesirov Complaint) in North Carolina state court. The lawsuit, styled Mesirov v. Good , is similar to the consolidated derivative action pending in Delaware Chancery Court and was filed against the same current directors and former directors and officers as the Delaware litigation. Duke Energy Corporation, Duke Energy Progress and Duke Energy Carolinas are named as nominal defendants. The Mesirov Complaint alleges that the Duke Energy Board of Directors was aware of Clean Water Act (CWA) compliance issues and failures to maintain structures in ash basins, but that the Board of Directors did not require Duke Energy Carolinas and Duke Energy Progress to take action to remedy deficiencies. The Mesirov Complaint further alleges that the Board of Directors sanctioned activities to avoid compliance with the law by allowing improper influence of NCDEQ to minimize regulation and by opposing previously anticipated citizen suit litigation. The Mesirov Complaint seeks corporate governance reforms and damages relating to costs associated with the Dan River release, remediation of ash basins that are out of compliance with the CWA and defending and payment of fines, penalties and settlements relating to criminal and civil investigations and lawsuits. The case was stayed until July 1, 2016. On July 5, 2016, the plaintiff filed a Notice of Voluntary Dismissal Without Prejudice, closing this matter. In addition to the above derivative complaints, in 2014, Duke Energy also received two shareholder litigation demand letters. The letters alleged that the members of the Board of Directors and certain officers breached their fiduciary duties by allowing the company to illegally dispose of and store coal ash pollutants. One of the letters also alleged a breach of fiduciary duty in the decision-making relating to the leadership changes following the close of the Progress Energy merger in July 2012. By letter dated September 4, 2015, attorneys for the shareholders were informed that, on the recommendation of the Demand Review Committee formed to consider such matters, the Board of Directors concluded not to pursue potential claims against individuals. One of the shareholders, Mitchell Pinsly, sent a formal demand for records and Duke Energy responded to this request. On October 30, 2015, shareholder Saul Bresalier filed a shareholder derivative complaint (Bresalier Complaint) in the U.S. District Court for the District of Delaware. The lawsuit alleges that several current and former Duke Energy officers and directors (Bresalier Defendants) breached their fiduciary duties in connection with coal ash environmental issues, the post-merger change in Chief Executive Officer (CEO) and oversight of political contributions. Duke Energy is named as a nominal defendant. The Bresalier Complaint contends that the Demand Review Committee failed to appropriately consider the shareholder’s earlier demand for litigation and improperly decided not to pursue claims against the Bresalier Defendants. The Bresalier Defendants filed a Motion to Dismiss the Bresalier litigation on January 15, 2016. In lieu of a response to the Motion to Dismiss, the plaintiff filed a Motion to Convert the Bresalier Defendants' Motion to Dismiss into a Motion for Summary Judgment and also for limited discovery. Following a hearing on June 15, 2016, the court denied the plaintiff's Motion to Convert and is requiring the parties to complete briefing on the Bresalier Defendants' Motion to Dismiss. On July 29, 2016, the Bresalier Defendants filed an Amended Motion to Dismiss. It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with these matters. Progress Energy Merger Shareholder Litigation On May 31, 2013, the Delaware Chancery Court consolidated four shareholder derivative lawsuits filed in 2012. The Court also appointed a lead plaintiff and counsel for plaintiffs and designated the case as In Re Duke Energy Corporation Derivative Litigation . The lawsuit names as defendants the 11 members of the Board of Directors who were also members of the pre-merger Board of Directors (Legacy Duke Energy Directors). Duke Energy is named as a nominal defendant. The case alleges claims for breach of fiduciary duties of loyalty and care in connection with the post-merger change in CEO. On December 10, 2015, the Legacy Duke Energy Directors filed a Motion to Dismiss the litigation. The court heard oral argument on the motion on May 9, 2016. Two shareholder Derivative Complaints, filed in 2012 in federal district court in Delaware, were consolidated as Tansey v. Rogers, et al. The case alleges claims against the Legacy Duke Energy Directors for breach of fiduciary duty and waste of corporate assets, as well as claims under Section 14(a) and 20(a) of the Exchange Act. Duke Energy is named as a nominal defendant. On December 21, 2015, Plaintiff filed a Consolidated Amended Complaint asserting the same claims contained in the original complaints. The Legacy Duke Energy Directors filed a Motion to Dismiss on February 19, 2016. On March 18, 2016, the Chancery Court Plaintiffs moved to intervene in the Tansey proceeding, asking the federal district court to stay the federal litigation in favor of the Delaware Chancery litigation, which was denied on June 27, 2016. Oral argument on the Legacy Duke Energy Directors' Motion to Dismiss is scheduled for August 24, 2016. It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with the remaining litigation. Price Reporting Cases Duke Energy Trading and Marketing, LLC (DETM), a non-operating Duke Energy affiliate, was a defendant, along with numerous other energy companies, in four class action lawsuits and a fifth single-plaintiff lawsuit pending in a consolidated federal court proceeding in Nevada. Each of these lawsuits contains similar claims that defendants allegedly manipulated natural gas markets by various means, including providing false information to natural gas trade publications and entering into unlawful arrangements and agreements in violation of the antitrust laws of the respective states. Plaintiffs seek damages in unspecified amounts. In February 2016, DETM reached agreements in principle to settle all of the pending lawsuits. Settlement of the single-plaintiff settlement was finalized and paid in March 2016. Settlement of the class action lawsuits are currently being finalized and will be subject to court approval. The settlement amounts are not material to Duke Energy. Brazil Expansion Lawsuit On August 9, 2011, the State of São Paulo sued Duke Energy International Geracao Paranapenema S.A. (DEIGP) in Brazilian state court. The lawsuit claims DEIGP is under a continuing obligation to expand installed generation capacity in the State of São Paulo by 15 percent pursuant to a stock purchase agreement under which DEIGP purchased generation assets from the state. On August 10, 2011, a judge granted an injunction ordering DEIGP to present a detailed expansion plan in satisfaction of the 15 percent obligation. DEIGP has previously taken a position that the expansion obligation is no longer viable given changes that have occurred in the electric energy sector since privatization. DEIGP submitted its proposed expansion plan on November 11, 2011, but reserved objections regarding enforceability. In January 2013, DEIGP filed appeals in the federal courts, which are still pending, regarding various procedural issues. A decision on the merits in the first instance court is also pending. It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with this matter. Brazil Generation Record drought conditions in Brazil during 2014 and 2015 negatively impacted DEIGP. A number of electric generators have filed lawsuits seeking relief in the Brazilian courts to mitigate hydrological exposure and diminishing dispatch levels. Some courts have granted injunction orders to limit the financial exposure of certain generators. The implication of these orders is that other electricity market participants not covered by the injunctions may be required to compensate for the financial impact of the liability limitations. The Independent Power Producer Association (APINE) filed one such lawsuit on behalf of DEIGP and other hydroelectric generators against the Brazilian electric regulatory agency (ANEEL). On July 2, 2015, an injunction was granted in favor of APINE limiting the financial exposure of DEIGP and the other plaintiff generators, until the merits of the lawsuit are determined. ANEEL's appeal of the injunction was denied on December 18, 2015. The outcome of these lawsuits is uncertain. It is not possible to predict the impact to Duke Energy from the outcome of these matters. Duke Energy Carolinas and Duke Energy Progress NCDEQ Notices of Violation In August 2014, NCDEQ issued an NOV for alleged groundwater violations at Duke Energy Progress' L.V. Sutton Plant. On March 10, 2015, NCDEQ issued a civil penalty of approximately $25 million to Duke Energy Progress for environmental damages related to the groundwater contamination at the L.V. Sutton Plant. On April 9, 2015, Duke Energy Progress filed a Petition for Contested Case hearing in the Office of Administrative Hearings. In February 2015, NCDEQ issued an NOV for alleged groundwater violations at Duke Energy Progress' Asheville Plant. Duke Energy Progress responded to NCDEQ regarding this NOV. On September 29, 2015, Duke Energy Progress and Duke Energy Carolinas entered into a settlement agreement with NCDEQ resolving all former, current and future groundwater penalties at all Duke Energy Carolinas and Duke Energy Progress coal facilities in North Carolina. Under the agreement, Duke Energy Progress paid approximately $6 million and Duke Energy Carolinas paid approximately $1 million . In addition to these payments, Duke Energy Progress and Duke Energy Carolinas will accelerate remediation actions at the Sutton, Asheville, Belews Creek and H.F. Lee plants. The ALJ entered a consent order resolving the contested case relating to the Sutton Plant and NCDEQ rescinded the NOVs relating to alleged groundwater violations at both the Sutton and Asheville plants. On October 13, 2015, the Southern Environmental Law Center (SELC), representing multiple conservation groups, filed a lawsuit in North Carolina Superior Court seeking judicial review of the order approving the settlement agreement with NCDEQ. The conservation groups contend that the ALJ exceeded his statutory authority in approving a settlement that provided for past, present, and future resolution of groundwater issues at facilities which were not at issue in the penalty appeal. On December 18, 2015, Duke Energy Carolinas and Duke Energy Progress filed a Motion to Dismiss the complaint. On February 12, 2016, the ALJ entered a new order clarifying that the dismissal of the contested case only applied to the specific issues before the ALJ in the Petition for Contested Case. On March 10, 2016, the court dismissed the SELC lawsuit based on the ALJ's entry of the new order. On February 8, 2016, NCDEQ assessed a penalty of approximately $6.8 million , including enforcement costs, against Duke Energy Carolinas related to storm water pipes and associated discharges at the Dan River Steam Station. Duke Energy Carolinas recorded a charge in December 2015 for this penalty. In March 2016, Duke Energy Carolinas filed an appeal of this penalty. A summary judgment hearing is set for August 22, 2016, for this proceeding. Duke Energy Carolinas cannot predict the outcome of this matter. NCDEQ State Enforcement Actions In the first quarter of 2013, SELC sent notices of intent to sue Duke Energy Carolinas and Duke Energy Progress related to alleged CWA violations from coal ash basins at two of their coal-fired power plants in North Carolina. NCDEQ filed enforcement actions against Duke Energy Carolinas and Duke Energy Progress alleging violations of water discharge permits and North Carolina groundwater standards. The cases have been consolidated and are being heard before a single judge. On August 16, 2013, NCDEQ filed an enforcement action against Duke Energy Carolinas and Duke Energy Progress related to their remaining plants in North Carolina, alleging violations of the CWA and violations of the North Carolina groundwater standards. Both of these cases have been assigned to the judge handling the enforcement actions discussed above. SELC is representing several environmental groups who have been permitted to intervene in these cases. On July 10, 2015, Duke Energy Carolinas and Duke Energy Progress filed two Motions for Partial Summary Judgment in the case on the basis that there is no longer either a genuine controversy or disputed material facts about the relief for seven of the 14 North Carolina plants with coal ash basins. On September 14, 2015, the court granted the Motions for Partial Summary Judgment pending court approval of the terms through an order. On April 4, 2016, the court issued an order granting Duke Energy Progress' Motion for Partial Summary Judgment for cases involving the H.F. Lee, Cape Fear and Weatherspoon plants. On June 1, 2016, the court issued an order granting Duke Energy Carolinas' and Duke Energy Progress' Motion for Partial Summary Judgment for cases involving the Asheville, Dan River, Riverbend and Sutton plants. The litigation is concluded for these seven plants. Litigation continues for the remaining seven plants. It is not possible to predict any liability or estimate any damages Duke Energy Carolinas or Duke Energy Progress might incur in connection with these matters. Federal Citizens Suits There are currently three cases filed in various North Carolina federal courts related to the Sutton, Buck and Mayo plants. Three other previously filed cases involving the Riverbend, Cape Fear and H.F. Lee plants were dismissed on June 7, 2016. On September 12, 2013, Cape Fear River Watch, Inc., Sierra Club and Waterkeeper Alliance filed a citizen suit in the Federal District Court for the Eastern District of North Carolina. The lawsuit alleges unpermitted discharges to surface water and groundwater violations at the Sutton Plant. On June 9, 2014, the court granted Duke Energy Progress' request to dismiss the groundwater claims but rejected its request to dismiss the surface water claims. In response to a motion filed by the SELC on August 1, 2014, the court modified the original order to dismiss only the plaintiff's federal law claim based on hydrologic connections at Sutton Lake. The claims related to the alleged state court violations of the permits are back in the case. On August 26, 2015, the court suspended the proceedings until further order from the court. On September 3, 2014, three citizen suits were filed by various environmental groups: (i) a citizen suit in the United States Court for the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Cape Fear Plant; (ii) in the United States Court for the Eastern District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the H.F. Lee Plant; and (iii) in the United States Court for the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Buck Steam Station. Motions to Stay or Dismiss the proceedings were filed in each of the three cases. The proceedings related to Cape Fear and H.F. Lee were dismissed on June 8, 2016, closing these matters. On October 20, 2015, the court issued an order denying the motions to stay or dismiss in the Buck proceedings. Duke Energy Carolinas' motion seeking appellate review of the District Court's decision relating to Buck was denied on January 29, 2016. The court has set an April 2017 trial date in the Buck proceeding. On June 13, 2016, the Roanoke River Basin Association filed a federal citizen suit in the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Mayo Plant. Duke Energy Progress expects to file a response to the complaint in third quarter of 2016. It is not possible to predict whether Duke Energy Carolinas or Duke Energy Progress will incur any liability or to estimate the damages, if any, they might incur in connection with these matters. Potential Groundwater Contamination Claims Beginning in May 2015, a number of residents living in the vicinity of the North Carolina facilities with ash basins received letters from NCDEQ advising them not to drink water from the private wells on their land tested by NCDEQ as the samples were found to have certain substances at levels higher than the criteria set by the North Carolina Department of Health and Human Services (DHHS). The criteria, in some cases, are considerably more stringent than federal drinking water standards established to protect human health and welfare. The Coal Ash Act requires additional groundwater monitoring and assessments for each of the 14 coal-fired plants in North Carolina, including sampling of private water supply wells. The data gathered through these Comprehensive Site Assessments (CSAs) will be used by NCDEQ to determine whether the water quality of these private water supply wells has been adversely impacted by the ash basins. Duke Energy has submitted CSAs documenting the results of extensive groundwater monitoring around coal ash basins at all 14 of the plants with coal ash basins. Generally, the data gathered through the installation of new monitoring wells and soil and water samples across the state have been consistent with historical data provided to state regulators over many years. The DHHS and NCDEQ sent follow-up letters on October 15, 2015, to residents near coal ash basin

Debt and Credit Facilities

Debt and Credit Facilities	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Debt And Credit Facilities	DEBT AND CREDIT FACILITIES SUMMARY OF SIGNIFICANT DEBT ISSUANCES The following table summarizes significant debt issuances (in millions). Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Maturity Interest Duke Energy Energy Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Florida Ohio Indiana Unsecured April 2016 (a) April 2023 2.875 % $ 350 $ 350 $ — $ — $ — $ — First Mortgage Bonds March 2016 (b) March 2023 2.500 % 500 — 500 — — — March 2016 (b) March 2046 3.875 % 500 — 500 — — — May 2016 (c) May 2046 3.750 % 500 — — — — 500 June 2016 (b) June 2046 3.700 % 250 — — — 250 — Secured Debt June 2016 (d) March 2020 1.196 % 183 — — 183 — — June 2016 (d) September 2022 1.731 % 150 — — 150 — — June 2016 (d) September 2029 2.538 % 436 — — 436 — — June 2016 (d) March 2033 2.858 % 250 — — 250 — — June 2016 (d) September 2036 3.112 % 275 — — 275 — — Total issuances $ 3,394 $ 350 $ 1,000 $ 1,294 $ 250 $ 500 (a) Proceeds were used to pay down outstanding commercial paper and for general corporate purposes. (b) Proceeds were used to fund capital expenditures for ongoing construction, capital maintenance and for general corporate purposes. (c) Proceeds were used to repay $325 million of unsecured debt due June 2016, $150 million of first mortgage bonds due July 2016 and for general corporate purposes. (d) Proceeds from the nuclear asset recovery bonds issued by DEFPF, a bankruptcy remote subsidiary of Duke Energy Florida, were used to acquire nuclear asset-recovery property from its parent, Duke Energy Florida. The nuclear asset-recovery bonds are payable only from and secured by the nuclear asset-recovery property. DEFPF is consolidated for financial reporting purposes; however, the nuclear asset-recovery bonds do not constitute a debt, liability or other legal obligation of, or interest in, Duke Energy Florida or any of its affiliates other than DEFPF. The assets of DEFPF, including the nuclear asset-recovery property, are not available to pay creditors of Duke Energy Florida or any of its affiliates. Duke Energy Florida used the proceeds from the sale to repay short-term borrowings under the intercompany money pool borrowing arrangement and make an equity distribution of $649 million to the ultimate parent, Duke Energy (Parent), which repaid short-term borrowings. The nuclear asset-recovery bonds are sequential pay amortizing bonds. The maturity date above represents the scheduled final maturity date for the bonds. See Notes 4 and 12 for additional information. CURRENT MATURITIES OF LONG-TERM DEBT The following table shows the significant components of Current maturities of long-term debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings. (in millions) Maturity Date Interest Rate June 30, 2016 Unsecured Debt Duke Energy (Parent) November 2016 2.150 % $ 500 Duke Energy (Parent) April 2017 1.009 % 400 Duke Energy May 2017 15.530 % 56 Secured Debt Duke Energy June 2017 2.075 % 45 First Mortgage Bonds Duke Energy Indiana July 2016 0.979 % 150 Duke Energy Carolinas December 2016 1.750 % 350 Duke Energy Progress March 2017 0.880 % 250 Tax-exempt Bonds Duke Energy Carolinas February 2017 3.600 % 77 Duke Energy Ohio (a) August 2027 1.280 % 50 Duke Energy Indiana (b) May 2035 1.092 % 44 Other (c) 420 Current maturities of long-term debt $ 2,342 (a) Represents Duke Energy Kentucky's bonds with a mandatory put in December 2016. (b) The bonds have a mandatory put in December 2016. (c) Includes capital lease obligations, amortizing debt and small bullet maturities. AVAILABLE CREDIT FACILITIES Master Credit Facility Duke Energy has a Master Credit Facility with a capacity of $7.5 billion through January 2020. The Duke Energy Registrants, excluding Progress Energy (Parent), have borrowing capacity under the Master Credit Facility up to a specified sublimit for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. Duke Energy Carolinas and Duke Energy Progress are also required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet obligations under plea agreements reached with the U.S. Department of Justice in 2015 related to violations at North Carolina facilities with ash basins. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility. June 30, 2016 Duke Duke Duke Duke Duke Duke Duke Energy Energy Energy Energy Energy Energy (in millions) Energy (Parent) Carolinas Progress Florida Ohio Indiana Facility size (a) $ 7,500 $ 3,475 $ 800 $ 1,000 $ 1,200 $ 425 $ 600 Reduction to backstop issuances Commercial paper (b) (1,673 ) (992 ) (300 ) (159 ) (47 ) (25 ) (150 ) Outstanding letters of credit (77 ) (70 ) (4 ) (2 ) (1 ) — — Tax-exempt bonds (116 ) — (35 ) — — — (81 ) Coal ash set-aside (500 ) — (250 ) (250 ) — — — Available capacity $ 5,134 $ 2,413 $ 211 $ 589 $ 1,152 $ 400 $ 369 (a) Represents the sublimit of each borrower. (b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies in the Condensed Consolidated Balance Sheets. Piedmont Bridge Facility In connection with the Merger Agreement with Piedmont, Duke Energy entered into a $4.9 billion Bridge Facility with Barclays. The Bridge Facility, if drawn upon, may be used (i) to fund the cash consideration for the transaction and (ii) to pay certain fees and expenses in connection with the transaction. In November 2015, Barclays syndicated its commitment under the Bridge Facility to a broader group of lenders. Duke Energy does not expect to draw upon the Bridge Facility. The amount of the Bridge Facility is reduced by any financings related to the Piedmont acquisition entered into by Duke Energy, and has accordingly been reduced to approximately $3.2 billion as a result of the Equity Forwards described in Note 13 and $1 billion of commitments under a term loan amended and restated as of August 1, 2016, described below. Refer to Note 2 for additional information on the Piedmont acquisition. Term Loan Facility On February 22, 2016, Duke Energy entered into a six-month term loan facility with commitments totaling $1.0 billion (the February 2016 Term Loan). As of June 30, 2016 , $100 million was outstanding under the February 2016 Term Loan. On August 1, 2016, Duke Energy and each of the lenders under the February 2016 Term Loan amended and restated certain terms of this facility, resulting in aggregate commitments of $1.5 billion and extending the maturity date to July 31, 2017. As of August 1, 2016, $100 million has been drawn under the amended and restated term loan (the August 2016 Term Loan). The remaining $1.4 billion of commitments under the August 2016 Term Loan can be drawn in up to two separate borrowings, which must occur no later than 90 calendar days following August 1, 2016. Any borrowings under the August 2016 Term Loan will be used to manage short-term liquidity, including funding a portion of the Piedmont acquisition, and for general corporate purposes. The terms and conditions of the August 2016 Term Loan are generally consistent with those governing Duke Energy’s Master Credit Facility. Solar Facilities Financing In August 2016, Emerald State Solar, LLC, an indirect wholly owned subsidiary of Duke Energy, entered into a portfolio financing of approximately 22 North Carolina Solar facilities. The $333 million term loan facility consists of Tranche A of $228 million due in June 2034 secured by substantially all the assets of the solar facilities and Tranche B of $105 million due in June 2020 secured by an Equity Contribution Agreement with Duke Energy. The initial interest rate on the loans is six months London Interbank Offered Rate (LIBOR) plus an applicable margin. The initial applicable margin is 1.75 percent with 0.125 percent increases every three years thereafter. In connection with this debt issuance, Emerald State Solar, LLC entered into two interest rate swaps to convert the substantial majority of the loan interest payments from variable rates to fixed rates of approximately 1.81 percent for Tranche A and 1.38 percent for Tranche B, plus the applicable margin.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL AND INTANGIBLE ASSETS GOODWILL The following table presents goodwill by reportable operating segment for Duke Energy. Duke Energy Regulated International Commercial (in millions) Utilities Energy Portfolio Total Goodwill at December 31, 2015 $ 15,950 $ 271 $ 122 $ 16,343 Foreign exchange changes — 14 — 14 Goodwill at June 30, 2016 $ 15,950 $ 285 $ 122 $ 16,357 Duke Energy Ohio Duke Energy Ohio's Goodwill balance of $920 million is included in the Regulated Utilities operating segment and presented net of accumulated impairment charges of $216 million on the Condensed Consolidated Balance Sheets at June 30, 2016 and December 31, 2015 . Progress Energy Progress Energy's Goodwill is included in the Regulated Utilities operating segment and there are no accumulated impairment charges.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2016
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS The Subsidiary Registrants engage in related party transactions in accordance with applicable state and federal commission regulations. Refer to the Condensed Consolidated Balance Sheets of the Subsidiary Registrants for balances due to or due from related parties. Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income. In addition to the amounts presented above, the Subsidiary Registrants record the impact on net income of other affiliate transactions, including rental of office space, participation in a money pool arrangement, other operational transactions and their proportionate share of certain charged expenses. See Note 6 to the Consolidated Financial Statements in the Annual Report on Form 10-K for more information regarding money pool. The net impact of these transactions was not material for the three and six months ended June 30, 2016 and 2015 for the Subsidiary Registrants. As discussed in Note 12 , certain trade receivables have been sold by Duke Energy Ohio and Duke Energy Indiana to CRC, an affiliate formed by a subsidiary of Duke Energy. The proceeds obtained from the sales of receivables are largely cash but also include a subordinated note from the affiliate for a portion of the purchase price. Duke Energy Ohio's nonregulated indirect subsidiary, Duke Energy Commercial Asset Management (DECAM), owned generating plants included in the Disposal Group sold to Dynegy on April 2, 2015. On April 1, 2015, Duke Energy Ohio distributed its indirect ownership interest in DECAM to a Duke Energy subsidiary and non-cash settled DECAM's intercompany loan payable of $294 million . Refer to Note 2 for further information on the sale of the Disposal Group. Intercompany Income Taxes Duke Energy and the Subsidiary Registrants file a consolidated federal income tax return and other state and jurisdictional returns. The Subsidiary Registrants have a tax sharing agreement with Duke Energy for the allocation of consolidated tax liabilities and benefits. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47

Derivatives and Hedging

Derivatives and Hedging	6 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	DERIVATIVES AND HEDGING The Duke Energy Registrants use commodity and interest rate contracts to manage commodity price risk and interest rate risk. The primary use of commodity derivatives is to hedge the generation portfolio against changes in the prices of electricity and natural gas. Interest rate swaps are used to manage interest rate risk associated with borrowings. All derivative instruments not identified as NPNS are recorded at fair value as assets or liabilities on the Condensed Consolidated Balance Sheets. Cash collateral related to derivative instruments executed under master netting arrangements is offset against the collateralized derivatives on the Condensed Consolidated Balance Sheets. The cash impacts of settled derivatives are recorded as operating activities on the Condensed Consolidated Statements of Cash Flows. INTEREST RATE RISK The Duke Energy Registrants are exposed to changes in interest rates as a result of their issuance or anticipated issuance of variable-rate and fixed-rate debt and commercial paper. Interest rate risk is managed by limiting variable-rate exposures to a percentage of total debt and by monitoring changes in interest rates. To manage risk associated with changes in interest rates, the Duke Energy Registrants may enter into interest rate swaps, U.S. Treasury lock agreements and other financial contracts. In anticipation of certain fixed-rate debt issuances, a series of forward-starting interest rate swaps may be executed to lock in components of current market interest rates. These instruments are later terminated prior to or upon the issuance of the corresponding debt. Cash Flow Hedges For a derivative designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the effective portion of the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction affects earnings. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt. Gains and losses reclassified out of Accumulated other comprehensive income (AOCI) for the three and six months ended June 30, 2016 , were not material. Duke Energy's interest rate derivatives designated as hedges include interest rate swaps used to hedge existing debt within the International Energy and Renewables' businesses. Undesignated Contracts Undesignated contracts include contracts not designated as a hedge because they are accounted for under regulatory accounting and contracts that do not qualify for hedge accounting. Duke Energy’s interest rate swaps for its Regulated Utilities operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense. As of June 30, 2016 , Duke Energy has entered into $1.4 billion of forward-starting interest rate swaps to manage interest rate exposure for the expected financing of the Piedmont acquisition. The swaps do not qualify for hedge accounting and are marked-to-market, with any gains or losses included within earnings. Unrealized losses on the swaps of $75 million and $168 million were included within Interest Expense on the Condensed Consolidated Statements of Operations for the three and six months ended June 30, 2016 . The swaps will be terminated in conjunction with the acquisition financing. See Note 2 for additional information related to the Piedmont acquisition. The following table shows notional amounts of outstanding derivatives related to interest rate risk. June 30, 2016 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges (a) $ 663 $ — $ — $ — $ — $ — Undesignated contracts 2,327 400 500 250 250 27 Total notional amount $ 2,990 $ 400 $ 500 $ 250 $ 250 $ 27 December 31, 2015 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges (a) $ 700 $ — $ — $ — $ — $ — Undesignated contracts 1,827 400 500 250 250 27 Total notional amount $ 2,527 $ 400 $ 500 $ 250 $ 250 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $463 million at June 30, 2016 and $497 million at December 31, 2015 . COMMODITY PRICE RISK The Duke Energy Registrants are exposed to the impact of changes in the prices of electricity, coal and natural gas. Exposure to commodity price risk is influenced by a number of factors including the term of contracts, the liquidity of markets and delivery locations. Regulated public utilities may have cost-based rate regulations and various other cost recovery mechanisms that result in a limited exposure to market volatility of commodity fuel prices. Financial derivative contracts, where approved by the respective state regulatory commissions, can be used to manage the risk of price volatility. At June 30, 2016 , substantially all of Duke Energy's open commodity derivative instruments were undesignated because they are accounted for under regulatory accounting. Mark-to-market gains or losses on contracts that use regulatory accounting are deferred as regulatory liabilities or regulatory assets, respectively. Undesignated contracts expire as late as 2020 . The Subsidiary Registrants utilize cost-tracking mechanisms, commonly referred to as fuel adjustment clauses. These clauses allow for the recovery of fuel and fuel-related costs, including settlements of undesignated derivatives for fuel commodities, and portions of purchased power costs through surcharges on customer rates. The difference between the costs incurred and the surcharge revenues is recorded as an adjustment to Fuel used in electric generation and purchased power – regulated or as Operating Revenues: Regulated electric on the Condensed Consolidated Statements of Operations, with an offsetting impact on regulatory assets or liabilities. Therefore, due to the regulatory accounting followed by the Subsidiary Registrants for undesignated derivatives, realized and unrealized gains and losses on undesignated commodity derivatives do not have an immediate impact on reported net income. Volumes The tables below show volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown. June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Electricity (gigawatt-hours) 7 — — — — — 7 Natural gas (millions of decatherms) 418 80 338 124 214 — — December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Electricity (gigawatt-hours) 70 — — — — 34 36 Natural gas (millions of decatherms) 398 66 332 117 215 — — LOCATION AND FAIR VALUE OF DERIVATIVE ASSETS AND LIABILITIES RECOGNIZED IN THE CONDENSED CONSOLIDATED BALANCE SHEETS The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Derivative Assets June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 64 $ 8 $ 20 $ 8 $ 12 $ 5 $ 31 Noncurrent 28 10 18 10 8 — — Total Derivative Assets – Commodity Contracts $ 92 $ 18 $ 38 $ 18 $ 20 $ 5 $ 31 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 3 $ — $ 3 $ 1 $ 2 $ — $ — Noncurrent 13 — 13 6 7 — — Total Derivative Assets – Interest Rate Contracts $ 16 $ — $ 16 $ 7 $ 9 $ — $ — Total Derivative Assets $ 108 $ 18 $ 54 $ 25 $ 29 $ 5 $ 31 Derivative Liabilities June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 84 $ 7 $ 77 $ 18 $ 59 $ — $ 1 Noncurrent 23 — 23 — 17 — — Total Derivative Liabilities – Commodity Contracts $ 107 $ 7 $ 100 $ 18 $ 76 $ — $ 1 Interest Rate Contracts Designated as Hedging Instruments Current $ 9 $ — $ — $ — $ — $ — $ — Noncurrent 52 — — — — — — Not Designated as Hedging Instruments Current (a) 170 — — — — 1 — Noncurrent 90 82 — — — 7 — Total Derivative Liabilities – Interest Rate Contracts $ 321 $ 82 $ — $ — $ — $ 8 $ — Total Derivative Liabilities $ 428 $ 89 $ 100 $ 18 $ 76 $ 8 $ 1 (a) Duke Energy amount includes $168 million related to forward-starting interest rate swaps associated with the Piedmont acquisition. Derivative Assets December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 12 $ — $ 1 $ — $ 1 $ 3 $ 7 Noncurrent 4 — 4 — 4 — — Total Derivative Assets – Commodity Contracts $ 16 $ — $ 5 $ — $ 5 $ 3 $ 7 Interest Rate Contracts Designated as Hedging Instruments Noncurrent $ 4 $ — $ — $ — $ — $ — $ — Not Designated as Hedging Instruments Current 6 — 6 2 2 — — Total Derivative Assets – Interest Rate Contracts $ 10 $ — $ 6 $ 2 $ 2 $ — $ — Total Derivative Assets $ 26 $ — $ 11 $ 2 $ 7 $ 3 $ 7 Derivative Liabilities December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 256 $ 32 $ 222 $ 77 $ 145 $ — $ — Noncurrent 100 8 92 16 71 — — Total Derivative Liabilities – Commodity Contracts $ 356 $ 40 $ 314 $ 93 $ 216 $ — $ — Interest Rate Contracts Designated as Hedging Instruments Current $ 11 $ — $ — $ — $ — $ — $ — Noncurrent 33 — — — — — — Not Designated as Hedging Instruments Current 4 — 3 — — 1 — Noncurrent 15 5 5 5 — 6 — Total Derivative Liabilities – Interest Rate Contracts $ 63 $ 5 $ 8 $ 5 $ — $ 7 $ — Total Derivative Liabilities $ 419 $ 45 $ 322 $ 98 $ 216 $ 7 $ — OFFSETTING ASSETS AND LIABILITIES The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The Gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below. Derivative Assets June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 67 $ 8 $ 23 $ 9 $ 14 $ 5 $ 31 Gross amounts offset (15 ) (3 ) (13 ) (6 ) (7 ) — — Net amounts presented in Current Assets: Other $ 52 $ 5 $ 10 $ 3 $ 7 $ 5 $ 31 Noncurrent Gross amounts recognized $ 41 $ 10 $ 31 $ 16 $ 15 $ — $ — Gross amounts offset (5 ) — (5 ) — (4 ) — — Net amounts presented in Investments and Other Assets: Other $ 36 $ 10 $ 26 $ 16 $ 11 $ — $ — Derivative Liabilities June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 263 $ 7 $ 77 $ 18 $ 59 $ 1 $ 1 Gross amounts offset (15 ) (3 ) (13 ) (6 ) (7 ) — — Net amounts presented in Current Liabilities: Other $ 248 $ 4 $ 64 $ 12 $ 52 $ 1 $ 1 Noncurrent Gross amounts recognized $ 165 $ 82 $ 23 $ — $ 17 $ 7 $ — Gross amounts offset (5 ) — (5 ) — (4 ) — — Net amounts presented in Deferred Credits and Other Liabilities: Other $ 160 $ 82 $ 18 $ — $ 13 $ 7 $ — Derivative Assets December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 18 $ — $ 7 $ 2 $ 3 $ 3 $ 7 Gross amounts offset (3 ) — (2 ) — (2 ) — — Net amounts presented in Current Assets: Other $ 15 $ — $ 5 $ 2 $ 1 $ 3 $ 7 Noncurrent Gross amounts recognized $ 8 $ — $ 4 $ — $ 4 $ — $ — Gross amounts offset (4 ) — (4 ) — (4 ) — — Net amounts presented in Investments and Other Assets: Other $ 4 $ — $ — $ — $ — $ — $ — Derivative Liabilities December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 271 $ 32 $ 225 $ 77 $ 145 $ 1 $ — Gross amounts offset (22 ) — (21 ) (1 ) (20 ) — — Net amounts presented in Current Liabilities: Other $ 249 $ 32 $ 204 $ 76 $ 125 $ 1 $ — Noncurrent Gross amounts recognized $ 148 $ 13 $ 97 $ 21 $ 71 $ 6 $ — Gross amounts offset (16 ) — (15 ) — (15 ) — — Net amounts presented in Deferred Credits and Other Liabilities: Other $ 132 $ 13 $ 82 $ 21 $ 56 $ 6 $ — OBJECTIVE CREDIT CONTINGENT FEATURES Certain derivative contracts contain objective credit contingent features. These features include the requirement to post cash collateral or letters of credit if specific events occur, such as a credit rating downgrade below investment grade. The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions. Amounts for Duke Energy Ohio and Duke Energy Indiana were not material. June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Aggregate fair value of derivatives in a net liability position $ 348 $ 89 $ 90 $ 18 $ 72 Fair value of collateral already posted — — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 348 89 90 18 72 December 31, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Aggregate fair value of derivatives in a net liability position $ 334 $ 45 $ 290 $ 93 $ 194 Fair value of collateral already posted 30 — 30 — 30 Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 304 45 260 93 164 The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative must be executed with the same counterparty under the same master netting arrangement. Amounts disclosed below represent the receivables related to the right to reclaim cash collateral under master netting arrangements. All receivables presented below were offset against net derivative positions on the Condensed Consolidated Balance Sheets. June 30, 2016 December 31, 2015 (in millions) Receivables Receivables Duke Energy $ — $ 30 Progress Energy — 30 Duke Energy Florida — 30

Investments in Debt and Equity

Investments in Debt and Equity Securities	6 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investments In Debt And Equity Securities	INVESTMENTS IN DEBT AND EQUITY SECURITIES The Duke Energy Registrants classify their investments in debt and equity securities as available-for-sale. Duke Energy’s available-for-sale securities are primarily comprised of investments held in (i) the nuclear decommissioning fund (NDTF) at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, (ii) grantor trusts at Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana related to Other Post-Retirement Benefit Obligations (OPEB) plans and (iii) Bison. Duke Energy classifies all other investments in debt and equity securities as long term, unless otherwise noted. Investment Trusts The investments within the NDTF investments and the Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana grantor trusts (Investment Trusts) are managed by independent investment managers with discretion to buy, sell, and invest pursuant to the objectives set forth by the trust agreements. The Duke Energy Registrants have limited oversight of the day-to-day management of these investments. As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt and equity securities within the Investment Trusts are considered other-than-temporary impairments and are recognized immediately. Investments within the Investment Trusts generally qualify for regulatory accounting, and accordingly realized and unrealized gains and losses are deferred as a regulatory asset or liability. However, certain investments held in Duke Energy Florida's NDTF, which were acquired in a settlement with Florida Municipal Joint Owners (FMJO), do not qualify for regulatory accounting. Except for other than temporary impairments of unrealized losses, unrealized gains and losses on these assets are included in other comprehensive income until realized. The other than temporary impairments of realized amounts and unrealized losses are included within Other income and expense, net on the Condensed Consolidated Statements of Operations. The value of these assets has not materially changed since the assets were acquired from FMJO. As a result, there is no material impact on earnings of the Duke Energy Registrants. Other Available-for-Sale Securities Unrealized gains and losses on all other available-for-sale securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an other than temporary impairment exists, the unrealized loss is included in earnings. There were no material credit losses as of June 30, 2016 and December 31, 2015 . DUKE ENERGY The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 189 $ — $ — $ 179 Equity securities 1,869 78 3,834 1,823 58 3,590 Corporate debt securities 22 1 480 7 8 432 Municipal bonds 12 1 307 5 1 185 U.S. government bonds 38 — 1,038 11 5 1,254 Other debt securities 1 3 144 — 4 177 Total NDTF $ 1,942 $ 83 $ 5,992 $ 1,846 $ 76 $ 5,817 Other Investments Cash and cash equivalents $ — $ — $ 27 $ — $ — $ 29 Equity securities 34 1 98 32 1 95 Corporate debt securities 2 1 97 1 3 92 Municipal bonds 6 1 80 3 1 74 U.S. government bonds 2 — 47 — — 45 Other debt securities — 1 57 — 2 62 Total Other Investments (a) $ 44 $ 4 $ 406 $ 36 $ 7 $ 397 Total Investments $ 1,986 $ 87 $ 6,398 $ 1,882 $ 83 $ 6,214 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts are considered other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 88 Due after one through five years 660 Due after five through 10 years 511 Due after 10 years 991 Total $ 2,250 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 64 $ 28 $ 118 $ 130 Realized losses 42 17 92 31 DUKE ENERGY CAROLINAS The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 66 $ — $ — $ 34 Equity securities 1,045 44 2,128 1,021 27 2,094 Corporate debt securities 13 1 309 3 5 292 Municipal bonds 2 — 42 1 — 33 U.S. government bonds 16 — 482 3 3 438 Other debt securities 1 3 136 — 4 147 Total NDTF $ 1,077 $ 48 $ 3,163 $ 1,028 $ 39 $ 3,038 Other Investments Other debt securities $ — $ 1 $ 3 $ — $ 1 $ 3 Total Other Investments (a) $ — $ 1 $ 3 $ — $ 1 $ 3 Total Investments $ 1,077 $ 49 $ 3,166 $ 1,028 $ 40 $ 3,041 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 6 Due after one through five years 198 Due after five through 10 years 235 Due after 10 years 533 Total $ 972 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 33 $ 17 $ 67 $ 107 Realized losses 19 11 56 23 PROGRESS ENERGY The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 123 $ — $ — $ 145 Equity securities 824 34 1,706 802 31 1,496 Corporate debt securities 9 — 171 4 3 140 Municipal bonds 10 1 265 4 1 152 U.S. government bonds 22 — 556 8 2 816 Other debt securities — — 8 — — 30 Total NDTF $ 865 $ 35 $ 2,829 $ 818 $ 37 $ 2,779 Other Investments Cash and cash equivalents $ — $ — $ 21 $ — $ — $ 18 Municipal bonds 4 — 47 3 — 45 Total Other Investments (a) $ 4 $ — $ 68 $ 3 $ — $ 63 Total Investments $ 869 $ 35 $ 2,897 $ 821 $ 37 $ 2,842 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 65 Due after one through five years 375 Due after five through 10 years 200 Due after 10 years 407 Total $ 1,047 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 31 $ 9 $ 50 $ 21 Realized losses 23 5 36 6 DUKE ENERGY PROGRESS The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 58 $ — $ — $ 110 Equity securities 614 28 1,379 596 25 1,178 Corporate debt securities 7 — 118 3 2 96 Municipal bonds 10 1 265 4 1 150 U.S. government bonds 14 — 281 6 2 486 Other debt securities — — 5 — — 18 Total NDTF $ 645 $ 29 $ 2,106 $ 609 $ 30 $ 2,038 Other Investments Cash and cash equivalents $ — $ — $ 1 $ — $ — $ 1 Total Other Investments (a) $ — $ — $ 1 $ — $ — $ 1 Total Investments $ 645 $ 29 $ 2,107 $ 609 $ 30 $ 2,039 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 14 Due after one through five years 191 Due after five through 10 years 154 Due after 10 years 310 Total $ 669 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 27 $ 8 $ 42 $ 17 Realized losses 20 4 31 5 DUKE ENERGY FLORIDA The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 65 $ — $ — $ 35 Equity securities 210 6 327 206 6 318 Corporate debt securities 2 — 53 1 1 44 Municipal bonds — — — — — 2 U.S. government bonds 8 — 275 2 — 330 Other debt securities — — 3 — — 12 Total NDTF $ 220 $ 6 $ 723 $ 209 $ 7 $ 741 Other Investments Cash and cash equivalents $ — $ — $ 4 $ — $ — $ 6 Municipal bonds 4 — 47 3 — 45 Total Other Investments (a) $ 4 $ — $ 51 $ 3 $ — $ 51 Total Investments $ 224 $ 6 $ 774 $ 212 $ 7 $ 792 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 51 Due after one through five years 184 Due after five through 10 years 46 Due after 10 years 97 Total $ 378 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 4 $ 1 $ 8 $ 4 Realized losses 3 1 5 1 DUKE ENERGY INDIANA The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value Other Investments Cash and cash equivalents $ — $ — $ — $ — $ — $ 2 Equity securities 28 — 73 27 — 71 Corporate debt securities — — 2 — — 2 Municipal bonds 1 1 29 — 1 26 Total Other Investments (a) $ 29 $ 1 $ 104 $ 27 $ 1 $ 101 Total Investments $ 29 $ 1 $ 104 $ 27 $ 1 $ 101 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset. The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 2 Due after one through five years 16 Due after five through 10 years 8 Due after 10 years 5 Total $ 31 Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were insignificant for the three and six months ended June 30, 2016 and 2015 .

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Fair value is the exchange price to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. The fair value definition focuses on an exit price versus the acquisition cost. Fair value measurements use market data or assumptions market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs may be readily observable, corroborated by market data, or generally unobservable. Valuation techniques maximize the use of observable inputs and minimize use of unobservable inputs. A midmarket pricing convention (the midpoint price between bid and ask prices) is permitted for use as a practical expedient. Fair value measurements are classified in three levels based on the fair value hierarchy: Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. An active market is one in which transactions for an asset or liability occur with sufficient frequency and volume to provide ongoing pricing information. Level 2 – A fair value measurement utilizing inputs other than quoted prices included in Level 1 that are observable, either directly or indirectly, for an asset or liability. Inputs include (i) quoted prices for similar assets or liabilities in active markets, (ii) quoted prices for identical or similar assets or liabilities in markets that are not active, (iii) and inputs other than quoted market prices that are observable for the asset or liability, such as interest rate curves and yield curves observable at commonly quoted intervals, volatilities and credit spreads. A Level 2 measurement cannot have more than an insignificant portion of its valuation based on unobservable inputs. Instruments in this category include non-exchange-traded derivatives, such as over-the-counter forwards, swaps and options; certain marketable debt securities; and financial instruments traded in less than active markets. Level 3 – Any fair value measurement which includes unobservable inputs for more than an insignificant portion of the valuation. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. Level 3 measurements may include longer-term instruments that extend into periods in which observable inputs are not available. Not Categorized – Certain investments are not categorized within the Fair Value hierarchy. These investments are measured based on the fair value of the underlying investments but may not be readily redeemable at that fair value. Fair value accounting guidance permits entities to elect to measure certain financial instruments that are not required to be accounted for at fair value, such as equity method investments or the company’s own debt, at fair value. The Duke Energy Registrants have not elected to record any of these items at fair value. Transfers between levels represent assets or liabilities that were previously (i) categorized at a higher level for which the inputs to the estimate became less observable or (ii) classified at a lower level for which the inputs became more observable during the period. The Duke Energy Registrant’s policy is to recognize transfers between levels of the fair value hierarchy at the end of the period. There were no transfers between levels during the three and six months ended June 30, 2016 and 2015 . Valuation methods of the primary fair value measurements disclosed below are as follows. Investments in equity securities The majority of investments in equity securities are valued using Level 1 measurements. Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the quarter. Principal active markets for equity prices include published exchanges such as Nasdaq Composite (NASDAQ) and New York Stock Exchange (NYSE). Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. There was no after-hours market activity that was required to be reflected in the reported fair value measurements. Investments in debt securities Most investments in debt securities are valued using Level 2 measurements because the valuations use interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. If the market for a particular fixed income security is relatively inactive or illiquid, the measurement is Level 3. Commodity derivatives Commodity derivatives with clearinghouses are classified as Level 1. Other commodity derivatives are primarily valued using internally developed discounted cash flow models which incorporate forward price, adjustments for liquidity (bid-ask spread) and credit or non-performance risk (after reflecting credit enhancements such as collateral), and are discounted to present value. Pricing inputs are derived from published exchange transaction prices and other observable data sources. In the absence of an active market, the last available price may be used. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for natural gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate the fair value of natural gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves. Interest rate derivatives Most over-the-counter interest rate contract derivatives are valued using financial models which utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties. DUKE ENERGY The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 3,834 $ 3,666 $ 1 $ — $ 167 Nuclear decommissioning trust fund debt securities 2,158 744 1,414 — — Other available-for-sale equity securities 98 98 — — — Other available-for-sale debt securities 308 74 230 4 — Derivative assets 108 2 72 34 — Total assets 6,506 4,584 1,717 38 167 Derivative liabilities (428 ) (1 ) (427 ) — — Net assets $ 6,078 $ 4,583 $ 1,290 $ 38 $ 167 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 3,590 $ 3,418 $ — $ — $ 172 Nuclear decommissioning trust fund debt securities 2,227 672 1,555 — — Other available-for-sale equity securities 95 95 — — — Other available-for-sale debt securities 302 75 222 5 — Derivative assets 26 — 16 10 — Total assets 6,240 4,260 1,793 15 172 Derivative liabilities (419 ) — (419 ) — — Net assets $ 5,821 $ 4,260 $ 1,374 $ 15 $ 172 The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Operating Revenues. There was no change to the Level 3 balance during the three months ended June 30, 2015 . Three Months Ended June 30, 2016 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 4 $ 2 $ 6 Purchases, sales, issuances and settlements: Purchases — 34 34 Settlements — (6 ) (6 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 4 4 Balance at end of period $ 4 $ 34 $ 38 Six Months Ended June 30, 2016 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 5 $ 10 $ 15 Purchases, sales, issuances and settlements: Purchases — 34 34 Sales (1 ) — (1 ) Settlements — (13 ) (13 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 3 3 Balance at end of period $ 4 $ 34 $ 38 Six Months Ended June 30, 2015 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 5 $ (1 ) $ 4 Total pretax realized or unrealized gains included in earnings — 18 18 Purchases, sales, issuances and settlements: Purchases — 24 24 Settlements — (22 ) (22 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 4 4 Balance at end of period $ 5 $ 23 $ 28 DUKE ENERGY CAROLINAS The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 2,128 $ 1,960 $ 1 $ — $ 167 Nuclear decommissioning trust fund debt securities 1,035 245 790 — — Other available-for-sale debt securities 3 — — 3 — Derivative assets 18 — 18 — — Total assets 3,184 2,205 809 3 167 Derivative liabilities (89 ) — (89 ) — — Net assets $ 3,095 $ 2,205 $ 720 $ 3 $ 167 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 2,094 $ 1,922 $ — $ — $ 172 Nuclear decommissioning trust fund debt securities 944 246 698 — — Other available-for-sale debt securities 3 — — 3 — Total assets 3,041 2,168 698 3 172 Derivative liabilities (45 ) — (45 ) — — Net assets $ 2,996 $ 2,168 $ 653 $ 3 $ 172 There was no change to the Level 3 balance during the three and six months ended June 30, 2016 and June 30, 2015 . PROGRESS ENERGY The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,706 $ 1,706 $ — Nuclear decommissioning trust fund debt securities 1,123 499 624 Other available-for-sale debt securities 68 21 47 Derivative assets 54 — 54 Total assets 2,951 2,226 725 Derivative liabilities (100 ) — (100 ) Net assets $ 2,851 $ 2,226 $ 625 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,496 $ 1,496 $ — Nuclear decommissioning trust fund debt securities 1,283 426 857 Other available-for-sale debt securities 63 18 45 Derivative assets 11 — 11 Total assets 2,853 1,940 913 Derivative liabilities (322 ) — (322 ) Net assets $ 2,531 $ 1,940 $ 591 DUKE ENERGY PROGRESS The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,379 $ 1,379 $ — Nuclear decommissioning trust fund debt securities and other 727 228 499 Other available-for-sale debt securities and other 1 1 — Derivative assets 25 — 25 Total assets 2,132 1,608 524 Derivative liabilities (18 ) — (18 ) Net assets $ 2,114 $ 1,608 $ 506 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,178 $ 1,178 $ — Nuclear decommissioning trust fund debt securities and other 860 141 719 Other available-for-sale debt securities and other 1 1 — Derivative assets 2 — 2 Total assets 2,041 1,320 721 Derivative liabilities (98 ) — (98 ) Net assets $ 1,943 $ 1,320 $ 623 DUKE ENERGY FLORIDA The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 327 $ 327 $ — Nuclear decommissioning trust fund debt securities and other 396 271 125 Other available-for-sale debt securities and other 51 4 47 Derivative assets 29 — 29 Total assets 803 602 201 Derivative liabilities (76 ) — (76 ) Net assets $ 727 $ 602 $ 125 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 318 $ 318 $ — Nuclear decommissioning trust fund debt securities and other 423 285 138 Other available-for-sale debt securities and other 51 6 45 Derivative assets 7 — 7 Total assets 799 609 190 Derivative liabilities (216 ) — (216 ) Net assets (liabilities) $ 583 $ 609 $ (26 ) DUKE ENERGY OHIO The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which are disclosed in Note 9 . June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Derivative assets $ 5 $ — $ — $ 5 Derivative liabilities (8 ) — (8 ) — Net (liabilities) assets $ (3 ) $ — $ (8 ) $ 5 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Derivative assets $ 3 $ — $ — $ 3 Derivative liabilities (7 ) — (7 ) — Net (liabilities) assets $ (4 ) $ — $ (7 ) $ 3 The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ — $ 7 Total pretax realized or unrealized gains included in earnings — (4 ) Purchases, sales, issuances and settlements: Purchases 5 — Sales — 5 Settlements — (3 ) Balance at end of period $ 5 $ 5 Derivatives (net) Six Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 3 $ (18 ) Total pretax realized or unrealized gains included in earnings — 21 Purchases, sales, issuances and settlements: Purchases 5 — Sales — 5 Settlements (2 ) (3 ) Total losses included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities (1 ) — Balance at end of period $ 5 $ 5 DUKE ENERGY INDIANA The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Other available-for-sale equity securities $ 73 $ 73 $ — $ — Other available-for-sale debt securities and other 31 — 31 — Derivative assets 31 2 — 29 Total assets 135 75 31 29 Derivative liabilities (1 ) (1 ) — — Net assets $ 134 $ 74 $ 31 $ 29 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Other available-for-sale equity securities $ 71 $ 71 $ — $ — Other available-for-sale debt securities and other 30 2 28 — Derivative assets 7 — — 7 Net assets $ 108 $ 73 $ 28 $ 7 The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 2 $ 3 Purchases, sales, issuances and settlements: Purchases 29 18 Settlements (6 ) (10 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities 4 6 Balance at end of period $ 29 $ 17 Derivatives (net) Six Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 7 $ 14 Purchases, sales, issuances and settlements: Purchases 29 18 Settlements (11 ) (19 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities 4 4 Balance at end of period $ 29 $ 17 QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS The following table includes quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. As of June 30, 2016 and December 31, 2015 , all Level 3 derivatives were financial transmission rights (FTRs). June 30, 2016 Fair Value of FTRs (in millions) Valuation Technique Unobservable Input Range Duke Energy $ 34 RTO auction pricing FTR price – per Megawatt-Hour (MWh) $ (1.64 ) - $ 8.64 Duke Energy Ohio 5 RTO auction pricing FTR price – per MWh 0.36 - 2.47 Duke Energy Indiana 29 RTO auction pricing FTR price – per MWh (1.64 ) - 8.64 December 31, 2015 Fair Value of FTRs (in millions) Valuation Technique Unobservable Input Range Duke Energy $ 10 RTO auction pricing FTR price – per MWh $ (0.74 ) - $ 7.29 Duke Energy Ohio 3 RTO auction pricing FTR price – per MWh 0.67 - 2.53 Duke Energy Indiana 7 RTO auction pricing FTR price – per MWh (0.74 ) - 7.29 OTHER FAIR VALUE DISCLOSURES The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements. June 30, 2016 December 31, 2015 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy $ 42,273 $ 47,953 $ 39,569 $ 42,537 Duke Energy Carolinas 9,360 10,874 8,367 9,156 Progress Energy 15,486 16,715 14,464 15,856 Duke Energy Progress 6,565 7,344 6,518 6,757 Duke Energy Florida 5,540 5,226 4,266 4,908 Duke Energy Ohio 1,887 2,134 1,598 1,724 Duke Energy Indiana 3,937 4,717 3,768 4,219 At both June 30, 2016 and December 31, 2015 , fair value of cash and cash equivalents, accounts and notes receivable, accounts payable, notes payable and commercial paper, and non-recourse notes payable of VIEs are not materially different from their carrying amounts because of the short-term nature of these instruments and/or because the stated rates approximate market rates.

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2016
Variable Interest Entities [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES A VIE is an entity that is evaluated for consolidation using more than a simple analysis of voting control. The analysis to determine whether an entity is a VIE considers contracts with an entity, credit support for an entity, the adequacy of the equity investment of an entity and the relationship of voting power to the amount of equity invested in an entity. This analysis is performed either upon the creation of a legal entity or upon the occurrence of an event requiring reevaluation, such as a significant change in an entity’s assets or activities. A qualitative analysis of control determines the party that consolidates a VIE. This assessment is based on (i) what party has the power to direct the activities of the VIE that most significantly impact its economic performance and (ii) what party has rights to receive benefits or is obligated to absorb losses that could potentially be significant to the VIE. The analysis of the party that consolidates a VIE is a continual reassessment. CONSOLIDATED VIEs The obligations of the consolidated VIEs discussed in the following paragraphs are nonrecourse to the Duke Energy registrants. The registrants have no requirement to provide liquidity to, purchase assets of or guarantee performance of these VIEs unless noted in the following paragraphs. No financial support was provided to any of the consolidated VIEs during the six months ended June 30, 2016 and the year ended December 31, 2015 , or is expected to be provided in the future, that was not previously contractually required. Receivables Financing – DERF / DEPR / DEFR Duke Energy Receivables Finance Company, LLC (DERF), Duke Energy Progress Receivables, LLC (DEPR) and Duke Energy Florida Receivables, LLC (DEFR) are bankruptcy remote, special purpose subsidiaries of Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, respectively. DERF, DEPR and DEFR are wholly owned limited liability companies with separate legal existence from their parent companies, and their assets are not generally available to creditors of their parent companies. On a revolving basis, DERF, DEPR and DEFR buy certain accounts receivable arising from the sale of electricity and related services from their parent companies. DERF, DEPR and DEFR borrow amounts under credit facilities to buy these receivables. Borrowing availability from the credit facilities is limited to the amount of qualified receivables purchased. The sole source of funds to satisfy the related debt obligations is cash collections from the receivables. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt. The most significant activity that impacts the economic performance of DERF, DEPR and DEFR are the decisions made to manage delinquent receivables. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida consolidate DERF, DEPR and DEFR, respectively, as they make those decisions. Receivables Financing – CRC CRC is a bankruptcy remote, special purpose entity indirectly owned by Duke Energy. On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity and related services from Duke Energy Ohio and Duke Energy Indiana. CRC borrows amounts under a credit facility to buy the receivables from Duke Energy Ohio and Duke Energy Indiana. Borrowing availability from the credit facility is limited to the amount of qualified receivables sold to CRC. The sole source of funds to satisfy the related debt obligation is cash collections from the receivables. Amounts borrowed under the credit facility are reflected on Duke Energy's Condensed Consolidated Balance Sheets as Long-Term Debt. The proceeds Duke Energy Ohio and Duke Energy Indiana receive from the sale of receivables to CRC are typically 75 percent cash and 25 percent in the form of a subordinated note from CRC. The subordinated note is a retained interest in the receivables sold. Depending on collection experience, additional equity infusions to CRC may be required by Duke Energy to maintain a minimum equity balance of $3 million . CRC is considered a VIE because (i) equity capitalization is insufficient to support its operations, (ii) power to direct the activities that most significantly impact the economic performance of the entity are not performed by the equity holder, and (iii) deficiencies in net worth of CRC are funded by Duke Energy. The most significant activities that impact the economic performance of CRC are decisions made to manage delinquent receivables. Duke Energy consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC. Receivables Financing – Credit Facilities The following table summarizes the amounts and expiration dates of the credit facilities described above. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt. Duke Energy Duke Energy Duke Energy Duke Energy Carolinas Progress Florida CRC DERF DEPR DEFR Expiration date December 2018 December 2018 February 2019 April 2019 Credit facility amount (in millions) $ 325 $ 425 $ 300 $ 225 Amounts borrowed at June 30, 2016 325 425 300 225 Amounts borrowed at December 31, 2015 325 425 254 225 Nuclear Asset-Recovery Bonds – DEFPF DEFPF is a bankruptcy remote, wholly owned special purpose subsidiary of Duke Energy Florida. DEFPF was formed in 2016 for the sole purpose of issuing nuclear asset-recovery bonds to finance Duke Energy Florida's unrecovered regulatory asset related to Crystal River Unit 3. In June 2016, DEFPF issued $ 1,294 million of senior secured bonds and used the proceeds to acquire nuclear asset-recovery property from Duke Energy Florida. The nuclear asset-recovery property acquired includes the right to impose, bill, collect and adjust a non-bypassable nuclear asset-recovery charge from all Duke Energy Florida retail customers until the bonds are paid in full and all financing costs have been recovered. The nuclear asset-recovery bonds are secured by the nuclear asset-recovery property, and cash collections from the nuclear asset-recovery charges are the sole source of funds to satisfy the debt obligation. The bondholders have no recourse to Duke Energy Florida. For additional information see Notes 4 and 6 . DEFPF is considered a VIE primarily because the equity capitalization is insufficient to support its operations. Duke Energy Florida has the power to direct the significant activities of the VIE as described above, and therefore Duke Energy Florida is considered the primary beneficiary and consolidates DEFPF. The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets. (in millions) June 30, 2016 Regulatory Assets: Current $ 34 Current Assets: Other 7 Regulatory Assets and Deferred Debits: Regulatory assets 1,194 Current maturities of long-term debt 35 Long-Term Debt 1,243 Renewables Certain Duke Energy renewable energy facilities are VIEs due to long-term fixed-price power purchase agreements. These fixed-price agreements effectively transfer commodity price risk to the buyer of the power. Certain other Duke Energy renewable energy facilities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. For certain VIEs, assets are restricted and cannot be pledged as collateral or sold to third parties without prior approval of debt holders. The activities that most significantly impact the economic performance of these renewable energy facilities were decisions associated with siting, negotiating purchase power agreements, engineering, procurement and construction, and decisions associated with ongoing operations and maintenance-related activities. Duke Energy consolidates the entities as it is responsible for all of these decisions. The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to renewables VIEs. (in millions) June 30, 2016 December 31, 2015 Current Assets: Other $ 223 $ 138 Property, plant and equipment, cost 2,578 2,015 Accumulated depreciation and amortization (376 ) (321 ) Current maturities of long-term debt 154 108 Long-Term Debt 866 968 Deferred Credits and Other Liabilities: Deferred income taxes 31 289 Deferred Credits and Other Liabilities: Other 277 33 NON-CONSOLIDATED VIEs The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. June 30, 2016 Duke Energy Duke Duke Energy Energy (in millions) Renewables Other Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 39 $ 58 Investments in equity method unconsolidated affiliates 222 252 474 — — Total assets $ 222 $ 252 $ 474 $ 39 $ 58 Other current liabilities — 3 3 — — Deferred credits and other liabilities — 13 13 — — Total liabilities $ — $ 16 $ 16 $ — $ — Net assets $ 222 $ 236 $ 458 $ 39 $ 58 December 31, 2015 Duke Energy Duke Duke Energy Energy (in millions) Renewables Other Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 47 $ 60 Investments in equity method unconsolidated affiliates 235 152 387 — — Total assets $ 235 $ 152 $ 387 $ 47 $ 60 Other current liabilities — 3 3 — — Deferred credits and other liabilities — 14 14 — — Total liabilities $ — $ 17 $ 17 $ — $ — Net assets $ 235 $ 135 $ 370 $ 47 $ 60 The Duke Energy Registrants are not aware of any situations where the maximum exposure to loss significantly exceeds the carrying values shown above except for the power purchase agreement with Ohio Valley Electric Corporation (OVEC), which is discussed below, and various guarantees, reflected in the table above as Deferred credits and other liabilities. For more information on various guarantees, refer to Note 5 . Renewables Duke Energy has investments in various renewable energy project entities. Some of these entities are VIEs due to long-term fixed-price power purchase agreements. These fixed-price agreements effectively transfer commodity price risk to the buyer of the power. Duke Energy does not consolidate these VIEs because power to direct and control key activities is shared jointly by Duke Energy and other owners. Other Duke Energy holds a 50 percent equity interest in Duke-American Transmission Company, LLC (DATC). DATC is considered a VIE due to insufficient equity at risk to permit DATC to finance its own activities without additional subordinated financial support. The activities that most significantly impact DATC’s economic performance are the decisions related to investing in existing and development of new transmission facilities. The power to direct these activities is jointly and equally shared by Duke Energy and the other joint venture partner, and therefore Duke Energy does not consolidate DATC. Duke Energy has a 40 percent equity interest and a 7.5 percent equity interest in ACP and Sabal Trail Transmission, LLC (Sabal Trail), respectively. These entities are considered VIEs as their equity is not sufficient to permit the entities to finance their activities without additional subordinated financial support. The activity that most significantly impacts the economic performance of both ACP and Sabal Trail is construction. Duke Energy does not control these activities and therefore does not consolidate ACP or Sabal Trail. OVEC Duke Energy Ohio’s 9 percent ownership interest in OVEC is considered a non-consolidated VIE. Through its ownership interest in OVEC, Duke Energy Ohio has a contractual arrangement to buy power from OVEC’s power plants through June 2040. Proceeds from the sale of power by OVEC to its power purchase agreement counterparties are designed to be sufficient to meet its operating expenses, fixed costs, debt amortization and interest expense, as well as earn a return on equity. Accordingly, the value of this contract is subject to variability due to fluctuations in power prices and changes in OVEC’s costs of business, including costs associated with its 2,256 MW of coal-fired generation capacity. Proposed environmental rulemaking could increase the costs of OVEC, which would be passed through to Duke Energy Ohio. CRC See discussion under Consolidated VIEs for additional information related to CRC. Amounts included in Receivables from affiliated companies in the above table for Duke Energy Ohio and Duke Energy Indiana reflect their retained interest in receivables sold to CRC. These subordinated notes held by Duke Energy Ohio and Duke Energy Indiana are stated at fair value. Carrying values of retained interests are determined by allocating carrying value of the receivables between assets sold and interests retained based on relative fair value. The allocated bases of the subordinated notes are not materially different than their face value because (i) the receivables generally turn over in less than two months, (ii) credit losses are reasonably predictable due to the broad customer base and lack of significant concentration, and (iii) the equity in CRC is subordinate to all retained interests and thus would absorb losses first. The hypothetical effect on fair value of the retained interests assuming both a 10 percent and a 20 percent unfavorable variation in credit losses or discount rates is not material due to the short turnover of receivables and historically low credit loss history. Interest accrues to Duke Energy Ohio and Duke Energy Indiana on the retained interests using the acceptable yield method. This method generally approximates the stated rate on the notes since the allocated basis and the face value are nearly equivalent. An impairment charge is recorded against the carrying value of both retained interests and purchased beneficial interest whenever it is determined that an other-than-temporary impairment has occurred. Key assumptions used in estimating fair value are detailed in the following table. Duke Energy Ohio Duke Energy Indiana 2016 2015 2016 2015 Anticipated credit loss ratio 0.5 % 0.6 % 0.3 % 0.3 % Discount rate 1.4 % 1.2 % 1.4 % 1.2 % Receivable turnover rate 13.2 % 12.9 % 10.6 % 10.6 % The following table shows the gross and net receivables sold. Duke Energy Ohio Duke Energy Indiana (in millions) June 30, 2016 December 31, 2015 June 30, 2016 December 31, 2015 Receivables sold $ 208 $ 233 $ 279 $ 260 Less: Retained interests 39 47 58 60 Net receivables sold $ 169 $ 186 $ 221 $ 200 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (in millions) 2016 2015 2016 2015 2016 2015 2016 2015 Sales Receivables sold $ 429 $ 425 $ 961 $ 1,069 $ 623 $ 637 $ 1,258 $ 1,353 Loss recognized on sale 2 2 5 5 2 2 5 5 Cash flows Cash proceeds from receivables sold 427 467 964 1,107 612 660 1,255 1,382 Collection fees received — 1 — 1 1 1 1 1 Return received on retained interests — 1 1 2 1 1 2 3 Cash flows from sales of receivables are reflected within Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows. Collection fees received in connection with servicing transferred accounts receivable are included in Operation, maintenance and other on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Operations and Comprehensive Income. The loss recognized on sales of receivables is calculated monthly by multiplying receivables sold during the month by the required discount. The required discount is derived monthly utilizing a three-year weighted average formula that considers charge-off history, late charge history and turnover history on the sold receivables, as well as a component for the time value of money. The discount rate, or component for the time value of money, is the prior month-end LIBOR plus a fixed rate of 1.00 percent .

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Common Stock	COMMON STOCK Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common stockholders, adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted average number of common stock outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted average number of common stock outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options and the Equity Forwards, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods. The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common stock outstanding to the diluted weighted average number of common shares outstanding. Three Months Ended June 30, Six Months Ended June 30, (in millions, except per-share amounts) 2016 2015 2016 2015 Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities $ 508 $ 600 $ 1,199 $ 1,372 Weighted average shares outstanding – basic 689 692 689 700 Equity Forwards 1 — — — Weighted average shares outstanding – diluted 690 692 689 700 Earnings per share from continuing operations attributable to Duke Energy common stockholders Basic $ 0.74 $ 0.87 $ 1.74 $ 1.96 Diluted $ 0.74 $ 0.87 $ 1.74 $ 1.96 Potentially dilutive items excluded from the calculation (a) 2 2 2 2 Dividends declared per common share $ 0.825 $ 0.795 $ 1.65 $ 1.59 (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met. Equity Forwards In March 2016, Duke Energy marketed an equity offering of 10.6 million shares of common stock. In lieu of issuing equity at the time of the offering, Duke Energy entered into Equity Forwards with Barclays. No amounts have or will be recorded in Duke Energy’s Condensed Consolidated Financial Statements with respect to the equity offering until settlements of the Equity Forwards occur. The Equity Forwards require Duke Energy to, at its election prior to June 30, 2017, either physically settle the transactions by issuing the total of 10.6 million of its common stock to Barclays in exchange for net proceeds at the then-applicable forward sale price specified by the agreements (initially $69.84 per share) or Duke Energy can net settle the transactions in whole or in part through the delivery or receipt of cash or shares. If Duke Energy had elected to net share settle the contract as of June 30, 2016 , Duke Energy would have been required to deliver 2.1 million shares. The forward sale price is subject to adjustment on a daily basis based on a floating interest rate factor and will decrease by other fixed amounts specified in the agreements. The net proceeds received upon settlement are expected to be used to finance a portion of the acquisition of Piedmont. Until settlement of the Equity Forwards, earnings per share dilution resulting from the agreements will be determined under the treasury stock method. Accelerated Stock Repurchase Program On April 6, 2015, Duke Energy entered into agreements with each of Goldman, Sachs & Co. and JPMorgan Chase Bank, National Association (the Dealers) to repurchase a total of $1.5 billion of Duke Energy common stock under an accelerated stock repurchase program (the ASR). Duke Energy made payments of $750 million to each of the Dealers and was delivered 16.6 million shares, with a total fair value of $1.275 billion , which represented approximately 85 percent of the total number of shares of Duke Energy common stock expected to be repurchased under the ASR. The company recorded the $1.5 billion payment as a reduction to common stock as of April 6, 2015. In June 2015, the Dealers delivered 3.2 million additional shares to Duke Energy to complete the ASR. Approximately 19.8 million shares, in total, were delivered to Duke Energy and retired under the ASR at an average price of $75.75 per share. The final number of shares repurchased was based upon the average of the daily volume weighted average stock prices of Duke Energy’s common stock during the term of the program, less a discount.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION For employee awards, equity classified stock-based compensation cost is measured at the service inception date or the grant date, based on the estimated achievement of certain performance metrics or the fair value of the award, and is recognized as expense or capitalized as a component of property, plant and equipment over the requisite service period. Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense, and stock-based compensation costs capitalized are included in the following table. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Restricted stock unit awards $ 10 $ 11 $ 17 $ 20 Performance awards 5 8 10 13 Pretax stock-based compensation cost $ 15 $ 19 $ 27 $ 33 Tax benefit associated with stock-based compensation expense $ 5 $ 7 $ 9 $ 12 Stock-based compensation costs capitalized 1 1 2 2

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS DEFINED BENEFIT RETIREMENT PLANS Duke Energy maintains, and the Subsidiary Registrants participate in, qualified, non-contributory defined benefit retirement plans. The plans cover most U.S. employees using a cash balance formula. Under a cash balance formula, a plan participant accumulates a retirement benefit consisting of pay credits equal to a percentage of current eligible earnings based on age or the combination of age and years of service, and interest credits. Certain employees are covered under plans that use a final average earnings formula. Under these average earnings formulas, a plan participant accumulates a retirement benefit equal to the sum of percentages of their (i) highest three-year or four-year average earnings, (ii) highest three-year or four-year average earnings in excess of covered compensation per year of participation (maximum of 35 years ) and/or (iii) highest three-year average earnings times years of participation in excess of 35 years . Duke Energy also maintains, and the Subsidiary Registrants participate in, non-qualified, non-contributory defined benefit retirement plans which cover certain executives. The qualified and non-qualified, non-contributory defined benefit plans are closed to new and rehired non-union and certain unionized employees. Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants’ contributions to its U.S. qualified defined benefit pension plans. Duke Energy did not make any contributions to its U.S. qualified defined benefit pension plans during the six months ended June 30, 2016 . Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Contributions $ 132 $ 42 $ 42 $ 21 $ 21 $ 1 $ 9 Net periodic benefit costs disclosed in the tables below represent the cost of the respective benefit plan for the periods presented. However, portions of the net periodic benefit costs disclosed in the tables below have been capitalized as a component of property, plant and equipment. Amounts presented in the tables below for the Subsidiary Registrants represent the amounts of pension and other post-retirement benefit costs allocated by Duke Energy for employees of the Subsidiary Registrants. Additionally, the Subsidiary Registrants are allocated their proportionate share of pension and post-retirement benefit costs for employees of Duke Energy’s shared services affiliate that provides support to the Subsidiary Registrants. These allocated amounts are included in the governance and shared service costs discussed in Note 8 . Duke Energy uses a December 31 measurement date for its defined benefit retirement plan assets and obligations. QUALIFIED PENSION PLANS The following tables include the components of net periodic pension costs for qualified pension plans. Three Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 37 $ 12 $ 10 $ 6 $ 5 $ 1 $ 2 Interest cost on projected benefit obligation 83 22 27 13 14 5 7 Expected return on plan assets (129 ) (36 ) (42 ) (20 ) (21 ) (7 ) (11 ) Amortization of actuarial loss 33 8 13 5 7 1 3 Amortization of prior service credit (4 ) (2 ) (1 ) (1 ) — — — Other 1 — — 1 — — — Net periodic pension costs $ 21 $ 4 $ 7 $ 4 $ 5 $ — $ 1 Three Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 39 $ 12 $ 11 $ 6 $ 5 $ 1 $ 2 Interest cost on projected benefit obligation 81 20 26 12 13 4 7 Expected return on plan assets (129 ) (33 ) (41 ) (21 ) (22 ) (7 ) (11 ) Amortization of actuarial loss 44 10 17 9 8 3 4 Amortization of prior service credit (3 ) (2 ) (1 ) (1 ) (1 ) — — Other 2 — — 1 1 — — Net periodic pension costs $ 34 $ 7 $ 12 $ 6 $ 4 $ 1 $ 2 Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 73 $ 24 $ 21 $ 12 $ 10 $ 2 $ 4 Interest cost on projected benefit obligation 166 43 53 25 28 10 14 Expected return on plan assets (258 ) (71 ) (84 ) (41 ) (42 ) (14 ) (21 ) Amortization of actuarial loss 66 16 27 11 14 2 6 Amortization of prior service credit (8 ) (4 ) (2 ) (1 ) — — — Other 4 1 1 1 — — — Net periodic pension costs $ 43 $ 9 $ 16 $ 7 $ 10 $ — $ 3 Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 79 $ 25 $ 22 $ 12 $ 10 $ 2 $ 5 Interest cost on projected benefit obligation 163 41 52 24 27 9 14 Expected return on plan assets (258 ) (69 ) (84 ) (41 ) (44 ) (13 ) (21 ) Amortization of actuarial loss 87 20 34 17 16 5 7 Amortization of prior service credit (7 ) (4 ) (2 ) (1 ) (1 ) — — Other 4 1 1 1 1 — — Net periodic pension costs $ 68 $ 14 $ 23 $ 12 $ 9 $ 3 $ 5 NON-QUALIFIED PENSION PLANS The following tables include the components of net periodic pension costs for non-qualified pension plans for registrants with non-qualified pension costs. Three Months Ended June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 3 1 1 1 1 Amortization of actuarial loss 2 — — — — Net periodic pension costs $ 6 $ 1 $ 1 $ 1 $ 1 Three Months Ended June 30, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 3 — 1 1 1 Amortization of actuarial loss 1 — 1 — — Net periodic pension costs $ 5 $ — $ 2 $ 1 $ 1 Six Months Ended June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 7 1 2 1 1 Amortization of actuarial loss 4 — 1 — — Net periodic pension costs $ 12 $ 1 $ 3 $ 1 $ 1 Six Months Ended June 30, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ 1 $ — $ — Interest cost on projected benefit obligation 7 1 2 1 1 Amortization of actuarial loss 3 — 1 — 1 Net periodic pension costs $ 11 $ 1 $ 4 $ 1 $ 2 OTHER POST-RETIREMENT BENEFIT PLANS Duke Energy provides, and the Subsidiary Registrants participate in, some health care and life insurance benefits for retired employees on a contributory and non-contributory basis. Employees are eligible for these benefits if they have met age and service requirements at retirement, as set forth in the plans. The health care benefits include medical, dental, vision, and prescription drug coverage and are subject to certain limitations, such as deductibles and co-payments. The following tables include the components of net periodic other post-retirement benefit costs. Three Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 1 $ — $ — $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 9 2 3 2 1 1 1 Expected return on plan assets (4 ) (2 ) — — — — (1 ) Amortization of actuarial loss (gain) 2 (1 ) 6 3 3 (1 ) — Amortization of prior service credit (36 ) (3 ) (25 ) (17 ) (9 ) — — Net periodic other post-retirement benefit costs $ (28 ) $ (4 ) $ (16 ) $ (12 ) $ (5 ) $ — $ — Three Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 1 $ 1 $ 1 $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 9 2 3 2 1 1 2 Expected return on plan assets (3 ) (2 ) — — — — — Amortization of actuarial loss (gain) 7 (1 ) 7 4 2 — (1 ) Amortization of prior service credit (35 ) (3 ) (25 ) (16 ) (7 ) — — Net periodic other post-retirement benefit costs $ (21 ) $ (3 ) $ (14 ) $ (10 ) $ (4 ) $ 1 $ 1 Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 2 $ — $ — $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 17 4 7 4 3 1 2 Expected return on plan assets (7 ) (4 ) — — — — (1 ) Amortization of actuarial loss (gain) 3 (2 ) 11 6 5 (1 ) (1 ) Amortization of prior service credit (71 ) (6 ) (51 ) (34 ) (18 ) — — Net periodic other post-retirement benefit costs $ (56 ) $ (8 ) $ (33 ) $ (24 ) $ (10 ) $ — $ — Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 3 $ 1 $ 1 $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 18 4 7 4 3 1 2 Expected return on plan assets (6 ) (4 ) — — — — — Amortization of actuarial loss (gain) 13 (1 ) 14 9 5 — (1 ) Amortization of prior service credit (70 ) (7 ) (51 ) (33 ) (16 ) — — Net periodic other post-retirement benefit costs $ (42 ) $ (7 ) $ (29 ) $ (20 ) $ (8 ) $ 1 $ 1 EMPLOYEE SAVINGS PLAN Duke Energy sponsors, and the Subsidiary Registrants participate in, an employee savings plan that covers substantially all U.S. employees. Most employees participate in a matching contribution formula where Duke Energy provides a matching contribution generally equal to 100 percent of employee before-tax and Roth 401(k) contributions of up to 6 percent of eligible pay per pay period. Dividends on Duke Energy shares held by the savings plan are charged to retained earnings when declared and shares held in the plan are considered outstanding in the calculation of basic and diluted earnings per share. For new and rehired non-union and certain unionized employees who are not eligible to participate in Duke Energy’s defined benefit plans, an additional employer contribution of 4 percent of eligible pay per pay period, subject to a three-year vesting requirement, is provided to the employee’s savings plan account. The following table presents employer contributions made by Duke Energy and expensed by the Subsidiary Registrants. Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Three Months Ended June 30, 2016 $ 39 $ 13 $ 12 $ 8 $ 4 $ 1 $ 2 2015 37 13 12 8 3 1 2 Six Months Ended June 30, 2016 $ 91 $ 31 $ 27 $ 19 $ 8 $ 2 $ 4 2015 86 29 26 19 7 2 4

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES TAXES ON FOREIGN EARNINGS As of December 31, 2015, Duke Energy's intention was to indefinitely reinvest foreign earnings of International Energy earned after December 31, 2014. In February 2016, Duke Energy announced it had initiated a process to divest the International Energy business segment, excluding the investment in NMC. Accordingly, Duke Energy no longer intends to indefinitely reinvest the undistributed earnings of International Energy. The Company recorded U.S. income taxes of approximately $ 4 million and $ 16 million for the three and six months ended June 30, 2016, respectively, related to such earnings and will prospectively provide U.S. income taxes on future foreign earnings. This change in the Company's intent, combined with the extension of bonus depreciation by Congress in late 2015, allows Duke Energy to more efficiently utilize foreign tax credits and reduce U.S. deferred tax liabilities associated with historic unremitted foreign earnings by approximately $ 95 million for the six months ended June 30, 2016. EFFECTIVE TAX RATES The effective tax rates from continuing operations for each of the Duke Energy Registrants are included in the following table. Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Duke Energy 31.8 % 35.6 % 27.2 % 33.6 % Duke Energy Carolinas 35.1 % 36.6 % 34.6 % 36.2 % Progress Energy 36.0 % 39.2 % 36.3 % 37.1 % Duke Energy Progress 35.5 % 40.6 % 35.4 % 36.0 % Duke Energy Florida 37.6 % 38.7 % 37.7 % 38.6 % Duke Energy Ohio 34.3 % 35.0 % 29.2 % 36.8 % Duke Energy Indiana 36.1 % 36.4 % 33.1 % 36.5 % The decrease in the effective tax rate for Duke Energy for the three and six months ended June 30, 2016 , is driven by lower income taxes on foreign earnings due to a more efficient utilization of foreign tax credits, as described above, and favorable impacts of finalizing federal tax audits. Refer to "Taxes on Foreign Earnings" above for additional information. The decrease in the effective tax rate for Duke Energy Carolinas for the three and six months ended June 30, 2016 , is primarily due to a favorable state resolution related to prior-year tax returns and favorable impacts of finalizing tax audits. The decrease in the effective tax rate for Progress Energy for the three months ended June 30, 2016 , is primarily due to a change in tax levelization. The decrease in the effective tax rate for Duke Energy Progress for the three months ended June 30, 2016 , is primarily due to a change in tax levelization. The decrease in the effective tax rate for Duke Energy Florida for the three months ended June 30, 2016 , is primarily due to an increase in AFUDC equity. The decrease in the effective tax rate for Duke Energy Ohio for the six months ended June 30, 2016 , is primarily due to a favorable prior-period adjustment for depreciation and other property, plant and equipment. The decrease in the effective tax rate for Duke Energy Indiana for the six months ended June 30, 2016 , is primarily due to a favorable prior-period adjustment for depreciation and other property, plant and equipment.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS For information on subsequent events related to acquisitions, regulatory matters, commitments and contingencies, and debt and credit facilities see Notes 2, 4, 5 and 6, respectively.

Organization and Basis of Pre25

Organization and Basis of Presentation (Policy)	6 Months Ended
	Jun. 30, 2016
Policy Text Block [Line Items]
Nature of Operations and Basis of Consolidation	NATURE OF OPERATIONS AND BASIS OF CONSOLIDATION Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) and Latin America primarily through its direct and indirect subsidiaries. Duke Energy’s subsidiaries include its subsidiary registrants, Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, LLC (Duke Energy Progress); Duke Energy Florida, LLC (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio) and Duke Energy Indiana, LLC (Duke Energy Indiana, formerly Duke Energy Indiana, Inc.). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its six separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants (Duke Energy Registrants). These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC. Substantially all of Duke Energy Carolinas’ operations qualify for regulatory accounting. Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by the FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida. Substantially all of Progress Energy’s operations qualify for regulatory accounting. Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC. Substantially all of Duke Energy Progress’ operations qualify for regulatory accounting. Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC. Substantially all of Duke Energy Florida’s operations qualify for regulatory accounting. Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in portions of Ohio and Kentucky, the generation and sale of electricity in portions of Kentucky, and the transportation and sale of natural gas in portions of Ohio and Kentucky. Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers and recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). References herein to Duke Energy Ohio collectively include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC. On April 2, 2015, Duke Energy completed the sale of its nonregulated Midwest generation business, which sold power into wholesale energy markets, to a subsidiary of Dynegy Inc. (Dynegy). See Note 2 for additional information. Substantially all of Duke Energy Ohio’s operations that remain after the sale qualify for regulatory accounting. Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC. Substantially all of Duke Energy Indiana’s operations qualify for regulatory accounting. On January 1, 2016, Duke Energy Indiana, an Indiana corporation, converted into an Indiana limited liability company.
Basis of Accounting	BASIS OF PRESENTATION Duke Energy completed the sale of Duke Energy Ohio's nonregulated Midwest generation business and Duke Energy Retail Sales (collectively, the Disposal Group), a retail sales business owned by Duke Energy, to Dynegy on April 2, 2015. The results of operations of these businesses prior to the date of sale have been classified as Discontinued Operations on the Condensed Consolidated Statements of Operations. Duke Energy has elected to present cash flows of discontinued operations combined with cash flows of continuing operations. Unless otherwise noted, the notes to these Condensed Consolidated Financial Statements exclude amounts related to discontinued operations. See Note 2 for additional information. These Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles (GAAP) in the U.S. for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP in the U.S. for annual financial statements. Since the interim Condensed Consolidated Financial Statements and Notes do not include all information and notes required by GAAP in the U.S. for annual financial statements, the Condensed Consolidated Financial Statements and other information included in this quarterly report should be read in conjunction with the Consolidated Financial Statements and Notes in the Duke Energy Registrants’ combined Annual Report on Form 10-K for the year ended December 31, 2015 . The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself. These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors.
Use of Estimates	In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.
Unbilled Revenue	UNBILLED REVENUE Revenues on sales of electricity and natural gas are recognized when service is provided or the product is delivered. Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules.
Excise Taxes	EXCISE TAXES Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, excise taxes are accounted for net. Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes on the Condensed Consolidated Statements of Operations were as follows.
New Accounting Standards	NEW ACCOUNTING STANDARDS The new accounting standards adopted for 2016 and 2015 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. The following accounting standard was adopted by the Duke Energy Registrants during 2015. Balance Sheet Presentation of Debt Issuance Costs. In April and August of 2015, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for the presentation of debt issuance costs. The core principle of this revised accounting guidance is that debt issuance costs are not assets, but adjustments to the carrying cost of debt. For Duke Energy, this revised accounting guidance was adopted retrospectively. The implementation of this accounting standard resulted in a reduction of Other within Regulatory Assets and Deferred Debits and in Long-Term Debt of $ 192 million and $ 170 million on the Condensed Consolidated Balance Sheets as of June 30, 2016, and December 31, 2015, respectively. The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by Duke Energy, as of June 30, 2016 . Revenue from Contracts with Customers. In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. For Duke Energy, the revised accounting guidance is effective for interim and annual periods beginning January 1, 2018. The guidance can be applied retrospectively to all prior reporting periods presented or retrospectively with a cumulative effect as of the initial date of application. Duke Energy is currently evaluating the requirements. The ultimate impact of the new standard has not yet been determined. Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet. For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2019, although it can be early adopted. The guidance is applied using a modified retrospective approach. Duke Energy is currently evaluating the requirements. Other than an expected increase in assets and liabilities, the ultimate impact of the new standard has not yet been determined. Stock-Based Compensation and Income Taxes. In March 2016, the FASB issued revised accounting guidance for stock-based compensation and the associated income taxes. This standard changes certain aspects of accounting for stock-based payment awards to employees including the accounting for income taxes, statutory tax withholding requirements, as well as the classification on the Condensed Consolidated Statements of Cash Flows. This guidance will be applied prospectively, retrospectively, or using a modified retrospective transition method depending on the item changed. For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2017, although it can be early adopted. Duke Energy is currently evaluating the requirements. The primary change expected is an increase in the volatility of income tax expense.
Duke Energy Ohio [Member]
Policy Text Block [Line Items]
Unbilled Revenue	Additionally, Duke Energy Ohio and Duke Energy Indiana sell nearly all of their retail accounts receivable to an affiliate, Cinergy Receivables Company, LLC (CRC), on a revolving basis. These transfers of receivables are accounted for as sales and include receivables for unbilled revenues. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 12 for further information. These receivables for unbilled revenues are shown in the table below.
Duke Energy Indiana [Member]
Policy Text Block [Line Items]
Unbilled Revenue	Additionally, Duke Energy Ohio and Duke Energy Indiana sell nearly all of their retail accounts receivable to an affiliate, Cinergy Receivables Company, LLC (CRC), on a revolving basis. These transfers of receivables are accounted for as sales and include receivables for unbilled revenues. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 12 for further information. These receivables for unbilled revenues are shown in the table below.

Organization and Basis of Pre26

Organization and Basis of Presentation (Tables)	6 Months Ended
	Jun. 30, 2016
Organization And Basis Of Presentation [Line Items]
Schedule of Excise Taxes	Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes on the Condensed Consolidated Statements of Operations were as follows. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy $ 87 $ 97 $ 178 $ 197 Duke Energy Carolinas 7 9 15 18 Progress Energy 50 57 96 106 Duke Energy Progress 4 4 9 8 Duke Energy Florida 46 53 87 98 Duke Energy Ohio 22 23 51 55 Duke Energy Indiana 8 8 16 18
Unbilled Revenues [Member]
Organization And Basis Of Presentation [Line Items]
Schedule Of Unbilled Revenues With Restricted Receivables	Unbilled revenues, which are included within Receivables and Receivables of variable interest entities (VIEs) on the Condensed Consolidated Balance Sheets, are presented in the following table. (in millions) June 30, 2016 December 31, 2015 Duke Energy $ 840 $ 748 Duke Energy Carolinas 330 283 Progress Energy 209 172 Duke Energy Progress 104 102 Duke Energy Florida 105 70 Duke Energy Ohio 2 3 Duke Energy Indiana 38 31
Duke Energy Ohio [Member] | Unbilled Revenues [Member]
Organization And Basis Of Presentation [Line Items]
Schedule Of Unbilled Revenues With Restricted Receivables	These receivables for unbilled revenues are shown in the table below. (in millions) June 30, 2016 December 31, 2015 Duke Energy Ohio $ 70 $ 71 Duke Energy Indiana 109 97
Duke Energy Indiana [Member] | Unbilled Revenues [Member]
Organization And Basis Of Presentation [Line Items]
Schedule Of Unbilled Revenues With Restricted Receivables	These receivables for unbilled revenues are shown in the table below. (in millions) June 30, 2016 December 31, 2015 Duke Energy Ohio $ 70 $ 71 Duke Energy Indiana 109 97

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Income Statement Disclosures	The following table presents the results of discontinued operations for the three and six months ended June 30, 2015 . Three Months Ended Six Months Ended June 30, 2015 June 30, 2015 Duke Duke Duke Energy Duke Energy (in millions) Energy Ohio Energy Ohio Operating Revenues $ — $ — $ 543 $ 412 Gain (Loss) on disposition 6 — (37 ) (44 ) (Loss) Income before income taxes (a) $ (80 ) $ (88 ) $ 67 $ 52 Income tax (benefit) expense (21 ) (23 ) 30 27 (Loss) Income from discontinued operations of the Disposal Group (59 ) (65 ) 37 25 Other, net of tax (b) 2 — (3 ) — (Loss) Income from Discontinued Operations, net of tax $ (57 ) $ (65 ) $ 34 $ 25 (a) The (Loss) Income before income taxes includes the pretax impact of a $71 million and $81 million charge for the agreement in principle reached in a lawsuit related to the Disposal Group for the three and six months ended June 30, 2015, respectively. Refer to Note 5 for further information related to the lawsuit. (b) Relates to discontinued operations of businesses not related to the Disposal Group and includes indemnifications provided for certain legal, tax and environmental matters, and foreign currency translation adjustments.

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2016
Segment Reporting Information [Line Items]
Business Segment Data	The following table provides the amount of Other net expense. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas $ (17 ) $ (10 ) $ (34 ) $ (18 ) Progress Energy (a) (45 ) (42 ) (94 ) (84 ) Duke Energy Progress (8 ) (4 ) (16 ) (8 ) Duke Energy Florida (5 ) (3 ) (9 ) (6 ) Duke Energy Ohio (10 ) (6 ) (19 ) (8 ) Duke Energy Indiana (5 ) (2 ) (7 ) (4 ) (a) Other for Progress Energy also includes interest expense on corporate debt instruments of $55 million and $111 million for the three and six months ended June 30, 2016 , respectively, and $59 million and $119 million for the three and six months ended June 30, 2015 , respectively. Three Months Ended June 30, 2016 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 5,090 $ 270 $ 112 $ 5,472 $ 12 $ — $ 5,484 Intersegment revenues 9 — — 9 17 (26 ) — Total revenues $ 5,099 $ 270 $ 112 $ 5,481 $ 29 $ (26 ) $ 5,484 Segment income (loss) (a)(b) $ 718 $ (102 ) $ 14 $ 630 $ (120 ) $ — $ 510 Add back noncontrolling interests 3 Loss from discontinued operations, net of tax (1 ) Net income $ 512 Segment assets $ 112,754 $ 3,131 $ 4,329 $ 120,214 $ 2,260 $ 180 $ 122,654 (a) Other includes after-tax charges for costs to achieve mergers of $69 million , primarily due to unrealized losses on forward-starting interest rate swaps related to the Piedmont acquisition, and cost savings initiatives of $15 million primarily due to severance costs. See Notes 2 and 9 for additional information related to the forward-starting interest rate swaps. (b) International Energy includes an after-tax impairment charge of $145 million . See Note 2 for additional information. Three Months Ended June 30, 2015 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 5,211 $ 287 $ 75 $ 5,573 $ 16 $ — $ 5,589 Intersegment revenues 9 — — 9 18 (27 ) — Total revenues $ 5,220 $ 287 $ 75 $ 5,582 $ 34 $ (27 ) $ 5,589 Segment income (loss) (a)(b) $ 632 $ 52 $ (30 ) $ 654 $ (51 ) $ (3 ) $ 600 Add back noncontrolling interests 4 Loss from discontinued operations, net of tax (c) (57 ) Net income $ 547 (a) Other includes after-tax costs to achieve the Progress Energy merger of $14 million . (b) Commercial Portfolio includes state tax expense of $41 million , resulting from changes to state apportionment factors due to the sale of the Disposal Group, that does not qualify for discontinued operations. Refer to Note 2 for further information related to the sale. (c) Includes the after-tax impact of $46 million for the agreement in principle reached in a lawsuit related to the Disposal Group. Refer to Note 5 for further information related to the lawsuit. Six Months Ended June 30, 2016 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 10,340 $ 516 $ 227 $ 11,083 $ 23 $ — $ 11,106 Intersegment revenues 18 — — 9 35 (53 ) — Total revenues $ 10,358 $ 516 $ 227 $ 11,092 $ 58 $ (53 ) $ 11,106 Segment income (loss) (a)(b) $ 1,413 $ 21 $ 41 $ 1,475 $ (274 ) $ — $ 1,201 Add back noncontrolling interests 8 Income from discontinued operations, net of tax 2 Net income $ 1,211 (a) Other includes after-tax charges for costs to achieve mergers of $143 million , primarily due to unrealized losses on forward-starting interest rate swaps related to the Piedmont acquisition, and cost savings initiatives of $27 million primarily due to severance costs. See Notes 2 and 9 for additional information related to the forward-starting interest rate swaps. (b) International Energy includes an after-tax impairment charge of $145 million . See Note 2 for additional information. Six Months Ended June 30, 2015 Total Regulated International Commercial Reportable (in millions) Utilities Energy Portfolio Segments Other Eliminations Consolidated Unaffiliated revenues $ 10,924 $ 560 $ 148 $ 11,632 $ 22 $ — $ 11,654 Intersegment revenues 19 — — 19 39 (58 ) — Total revenues $ 10,943 $ 560 $ 148 $ 11,651 $ 61 $ (58 ) $ 11,654 Segment income (loss) (a)(b) $ 1,406 $ 88 $ (23 ) $ 1,471 $ (94 ) $ (4 ) $ 1,373 Add back noncontrolling interests 7 Income from discontinued operations, net of tax (c) 34 Net income $ 1,414 (a) Other includes after-tax costs to achieve the Progress Energy merger of $27 million . (b) Commercial Portfolio includes state tax expense of $41 million , resulting from changes to state apportionment factors due to the sale of the Disposal Group, that does not qualify for discontinued operations. Refer to Note 2 for further information related to the sale. (c) Includes after-tax impact of $53 million for the agreement in principle reached in a lawsuit related to the Disposal Group. Refer to Note 5 for further information related to the lawsuit.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2016
Public Utilities, General Disclosures [Line Items]
Schedule of Potential Plant Retirements	The table below contains the net carrying value of generating facilities planned for retirement or included in recent IRPs as evaluated for potential retirement due to a lack of requisite environmental control equipment. Dollar amounts in the table below are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of June 30, 2016 . Remaining Net Capacity Book Value (a) (in MW) (in millions) Progress Energy and Duke Energy Florida Crystal River Units 1 and 2 873 126 Duke Energy Indiana Wabash River Unit 6 (b) 318 34 Gallagher Units 2 and 4 (c) 280 135 Total Duke Energy 1,471 295 (a) Remaining net book value amounts exclude any capitalized asset retirement costs. (b) In April 2016, Wabash River 6 terminated coal burning operations and is targeted for retirement by the end of 2016. The total net book value of $93 million for the retail portion of Wabash River Unit 6 and the retail portion of capitalized asset retirement costs for Wabash River Units 2 through 6 is classified as Generation facilities to be retired, net on Duke Energy Indiana's Condensed Consolidated Balance Sheet at June 30, 2016 . (c) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the proposed settlement of Edwardsport IGCC matters.

Commitments and Contingencies (

Commitments and Contingencies (Table)	6 Months Ended
	Jun. 30, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Additional Possible Losses in Excess of Recorded Environmental Reserves	Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below. (in millions) Duke Energy $ 75 Duke Energy Carolinas 22 Duke Energy Ohio 42 Duke Energy Indiana 7
Schedule of Loss Contingencies	The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos related reserves and the exit obligation discussed above related to the termination of an EPC contract. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above. (in millions) June 30, 2016 December 31, 2015 Reserves for Legal Matters Duke Energy $ 110 $ 166 Duke Energy Carolinas 14 11 Progress Energy 52 54 Duke Energy Progress 6 6 Duke Energy Florida 30 31 Duke Energy Ohio 4 80
Reserve for Environmental Costs [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Loss Contingencies	The following tables contain information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Other within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheets. Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Balance at beginning of period $ 97 $ 10 $ 17 $ 3 $ 14 $ 54 $ 12 Provisions/adjustments 28 3 4 1 3 1 21 Cash reductions (7 ) (2 ) (4 ) (1 ) (3 ) (1 ) (1 ) Balance at end of period $ 118 $ 11 $ 17 $ 3 $ 14 $ 54 $ 32 Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Balance at beginning of period $ 97 $ 10 $ 17 $ 5 $ 12 $ 54 $ 10 Provisions/adjustments 5 — 2 — 2 1 3 Cash reductions (4 ) — (2 ) (1 ) (1 ) (1 ) (1 ) Balance at end of period $ 98 $ 10 $ 17 $ 4 $ 13 $ 54 $ 12

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	The following table summarizes significant debt issuances (in millions). Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Maturity Interest Duke Energy Energy Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Florida Ohio Indiana Unsecured April 2016 (a) April 2023 2.875 % $ 350 $ 350 $ — $ — $ — $ — First Mortgage Bonds March 2016 (b) March 2023 2.500 % 500 — 500 — — — March 2016 (b) March 2046 3.875 % 500 — 500 — — — May 2016 (c) May 2046 3.750 % 500 — — — — 500 June 2016 (b) June 2046 3.700 % 250 — — — 250 — Secured Debt June 2016 (d) March 2020 1.196 % 183 — — 183 — — June 2016 (d) September 2022 1.731 % 150 — — 150 — — June 2016 (d) September 2029 2.538 % 436 — — 436 — — June 2016 (d) March 2033 2.858 % 250 — — 250 — — June 2016 (d) September 2036 3.112 % 275 — — 275 — — Total issuances $ 3,394 $ 350 $ 1,000 $ 1,294 $ 250 $ 500 (a) Proceeds were used to pay down outstanding commercial paper and for general corporate purposes. (b) Proceeds were used to fund capital expenditures for ongoing construction, capital maintenance and for general corporate purposes. (c) Proceeds were used to repay $325 million of unsecured debt due June 2016, $150 million of first mortgage bonds due July 2016 and for general corporate purposes. (d) Proceeds from the nuclear asset recovery bonds issued by DEFPF, a bankruptcy remote subsidiary of Duke Energy Florida, were used to acquire nuclear asset-recovery property from its parent, Duke Energy Florida. The nuclear asset-recovery bonds are payable only from and secured by the nuclear asset-recovery property. DEFPF is consolidated for financial reporting purposes; however, the nuclear asset-recovery bonds do not constitute a debt, liability or other legal obligation of, or interest in, Duke Energy Florida or any of its affiliates other than DEFPF. The assets of DEFPF, including the nuclear asset-recovery property, are not available to pay creditors of Duke Energy Florida or any of its affiliates. Duke Energy Florida used the proceeds from the sale to repay short-term borrowings under the intercompany money pool borrowing arrangement and make an equity distribution of $649 million to the ultimate parent, Duke Energy (Parent), which repaid short-term borrowings. The nuclear asset-recovery bonds are sequential pay amortizing bonds. The maturity date above represents the scheduled final maturity date for the bonds. See Notes 4 and 12 for additional information.
Schedule Of Debt	The following table shows the significant components of Current maturities of long-term debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings. (in millions) Maturity Date Interest Rate June 30, 2016 Unsecured Debt Duke Energy (Parent) November 2016 2.150 % $ 500 Duke Energy (Parent) April 2017 1.009 % 400 Duke Energy May 2017 15.530 % 56 Secured Debt Duke Energy June 2017 2.075 % 45 First Mortgage Bonds Duke Energy Indiana July 2016 0.979 % 150 Duke Energy Carolinas December 2016 1.750 % 350 Duke Energy Progress March 2017 0.880 % 250 Tax-exempt Bonds Duke Energy Carolinas February 2017 3.600 % 77 Duke Energy Ohio (a) August 2027 1.280 % 50 Duke Energy Indiana (b) May 2035 1.092 % 44 Other (c) 420 Current maturities of long-term debt $ 2,342 (a) Represents Duke Energy Kentucky's bonds with a mandatory put in December 2016. (b) The bonds have a mandatory put in December 2016. (c) Includes capital lease obligations, amortizing debt and small bullet maturities.
Schedule Of Line Of Credit Facilities	Duke Energy has a Master Credit Facility with a capacity of $7.5 billion through January 2020. The Duke Energy Registrants, excluding Progress Energy (Parent), have borrowing capacity under the Master Credit Facility up to a specified sublimit for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. Duke Energy Carolinas and Duke Energy Progress are also required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet obligations under plea agreements reached with the U.S. Department of Justice in 2015 related to violations at North Carolina facilities with ash basins. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility. June 30, 2016 Duke Duke Duke Duke Duke Duke Duke Energy Energy Energy Energy Energy Energy (in millions) Energy (Parent) Carolinas Progress Florida Ohio Indiana Facility size (a) $ 7,500 $ 3,475 $ 800 $ 1,000 $ 1,200 $ 425 $ 600 Reduction to backstop issuances Commercial paper (b) (1,673 ) (992 ) (300 ) (159 ) (47 ) (25 ) (150 ) Outstanding letters of credit (77 ) (70 ) (4 ) (2 ) (1 ) — — Tax-exempt bonds (116 ) — (35 ) — — — (81 ) Coal ash set-aside (500 ) — (250 ) (250 ) — — — Available capacity $ 5,134 $ 2,413 $ 211 $ 589 $ 1,152 $ 400 $ 369 (a) Represents the sublimit of each borrower. (b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies in the Condensed Consolidated Balance Sheets.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2016
Goodwill [Line Items]
Goodwill By Reportable Operating Segment	The following table presents goodwill by reportable operating segment for Duke Energy. Duke Energy Regulated International Commercial (in millions) Utilities Energy Portfolio Total Goodwill at December 31, 2015 $ 15,950 $ 271 $ 122 $ 16,343 Foreign exchange changes — 14 — 14 Goodwill at June 30, 2016 $ 15,950 $ 285 $ 122 $ 16,357

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2016
Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47
Progress Energy [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47
Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47
Duke Energy Florida [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47
Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47
Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended June 30, Six Months Ended June 30, (in millions) 2016 2015 2016 2015 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 199 $ 202 $ 416 $ 421 Indemnification coverages (b) 5 6 11 12 JDA revenue (c) 2 14 11 40 JDA expense (c) 50 38 91 95 Progress Energy Corporate governance and shared service expenses (a) $ 160 $ 172 $ 334 $ 339 Indemnification coverages (b) 9 9 17 19 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Progress Corporate governance and shared service expenses (a) $ 89 $ 93 $ 189 $ 194 Indemnification coverages (b) 4 4 7 8 JDA revenue (c) 50 38 91 95 JDA expense (c) 2 14 11 40 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 79 $ 145 $ 145 Indemnification coverages (b) 5 5 10 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 87 $ 103 $ 172 $ 188 Indemnification coverages (b) 1 1 2 4 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 89 $ 83 $ 183 $ 172 Indemnification coverages (b) 2 2 4 4 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources and employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations and Comprehensive Income.
Intercompany Income Tax Receivable/Payable	The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana June 30, 2016 Intercompany income tax receivable $ 10 $ 90 $ — $ — $ 15 $ 6 Intercompany income tax payable — — 11 48 — — December 31, 2015 Intercompany income tax receivable $ 122 $ 120 $ 104 $ — $ 54 $ — Intercompany income tax payable — — — 96 — 47

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	6 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts of Outstanding Derivative Positions	The tables below show volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown. June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Electricity (gigawatt-hours) 7 — — — — — 7 Natural gas (millions of decatherms) 418 80 338 124 214 — — December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Electricity (gigawatt-hours) 70 — — — — 34 36 Natural gas (millions of decatherms) 398 66 332 117 215 — — The following table shows notional amounts of outstanding derivatives related to interest rate risk. June 30, 2016 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges (a) $ 663 $ — $ — $ — $ — $ — Undesignated contracts 2,327 400 500 250 250 27 Total notional amount $ 2,990 $ 400 $ 500 $ 250 $ 250 $ 27 December 31, 2015 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges (a) $ 700 $ — $ — $ — $ — $ — Undesignated contracts 1,827 400 500 250 250 27 Total notional amount $ 2,527 $ 400 $ 500 $ 250 $ 250 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $463 million at June 30, 2016 and $497 million at December 31, 2015 .
Location And Fair Value Of Derivatives Recognized in the Condensed Consolidated Balance Sheets	The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Derivative Assets June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 64 $ 8 $ 20 $ 8 $ 12 $ 5 $ 31 Noncurrent 28 10 18 10 8 — — Total Derivative Assets – Commodity Contracts $ 92 $ 18 $ 38 $ 18 $ 20 $ 5 $ 31 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 3 $ — $ 3 $ 1 $ 2 $ — $ — Noncurrent 13 — 13 6 7 — — Total Derivative Assets – Interest Rate Contracts $ 16 $ — $ 16 $ 7 $ 9 $ — $ — Total Derivative Assets $ 108 $ 18 $ 54 $ 25 $ 29 $ 5 $ 31 Derivative Liabilities June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 84 $ 7 $ 77 $ 18 $ 59 $ — $ 1 Noncurrent 23 — 23 — 17 — — Total Derivative Liabilities – Commodity Contracts $ 107 $ 7 $ 100 $ 18 $ 76 $ — $ 1 Interest Rate Contracts Designated as Hedging Instruments Current $ 9 $ — $ — $ — $ — $ — $ — Noncurrent 52 — — — — — — Not Designated as Hedging Instruments Current (a) 170 — — — — 1 — Noncurrent 90 82 — — — 7 — Total Derivative Liabilities – Interest Rate Contracts $ 321 $ 82 $ — $ — $ — $ 8 $ — Total Derivative Liabilities $ 428 $ 89 $ 100 $ 18 $ 76 $ 8 $ 1 (a) Duke Energy amount includes $168 million related to forward-starting interest rate swaps associated with the Piedmont acquisition. Derivative Assets December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 12 $ — $ 1 $ — $ 1 $ 3 $ 7 Noncurrent 4 — 4 — 4 — — Total Derivative Assets – Commodity Contracts $ 16 $ — $ 5 $ — $ 5 $ 3 $ 7 Interest Rate Contracts Designated as Hedging Instruments Noncurrent $ 4 $ — $ — $ — $ — $ — $ — Not Designated as Hedging Instruments Current 6 — 6 2 2 — — Total Derivative Assets – Interest Rate Contracts $ 10 $ — $ 6 $ 2 $ 2 $ — $ — Total Derivative Assets $ 26 $ — $ 11 $ 2 $ 7 $ 3 $ 7 Derivative Liabilities December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Commodity Contracts Not Designated as Hedging Instruments Current $ 256 $ 32 $ 222 $ 77 $ 145 $ — $ — Noncurrent 100 8 92 16 71 — — Total Derivative Liabilities – Commodity Contracts $ 356 $ 40 $ 314 $ 93 $ 216 $ — $ — Interest Rate Contracts Designated as Hedging Instruments Current $ 11 $ — $ — $ — $ — $ — $ — Noncurrent 33 — — — — — — Not Designated as Hedging Instruments Current 4 — 3 — — 1 — Noncurrent 15 5 5 5 — 6 — Total Derivative Liabilities – Interest Rate Contracts $ 63 $ 5 $ 8 $ 5 $ — $ 7 $ — Total Derivative Liabilities $ 419 $ 45 $ 322 $ 98 $ 216 $ 7 $ —
Offsetting Assets	Derivative Assets December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 18 $ — $ 7 $ 2 $ 3 $ 3 $ 7 Gross amounts offset (3 ) — (2 ) — (2 ) — — Net amounts presented in Current Assets: Other $ 15 $ — $ 5 $ 2 $ 1 $ 3 $ 7 Noncurrent Gross amounts recognized $ 8 $ — $ 4 $ — $ 4 $ — $ — Gross amounts offset (4 ) — (4 ) — (4 ) — — Net amounts presented in Investments and Other Assets: Other $ 4 $ — $ — $ — $ — $ — $ — The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The Gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below. Derivative Assets June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 67 $ 8 $ 23 $ 9 $ 14 $ 5 $ 31 Gross amounts offset (15 ) (3 ) (13 ) (6 ) (7 ) — — Net amounts presented in Current Assets: Other $ 52 $ 5 $ 10 $ 3 $ 7 $ 5 $ 31 Noncurrent Gross amounts recognized $ 41 $ 10 $ 31 $ 16 $ 15 $ — $ — Gross amounts offset (5 ) — (5 ) — (4 ) — — Net amounts presented in Investments and Other Assets: Other $ 36 $ 10 $ 26 $ 16 $ 11 $ — $ —
Offsetting Liabilities	Derivative Liabilities December 31, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 271 $ 32 $ 225 $ 77 $ 145 $ 1 $ — Gross amounts offset (22 ) — (21 ) (1 ) (20 ) — — Net amounts presented in Current Liabilities: Other $ 249 $ 32 $ 204 $ 76 $ 125 $ 1 $ — Noncurrent Gross amounts recognized $ 148 $ 13 $ 97 $ 21 $ 71 $ 6 $ — Gross amounts offset (16 ) — (15 ) — (15 ) — — Net amounts presented in Deferred Credits and Other Liabilities: Other $ 132 $ 13 $ 82 $ 21 $ 56 $ 6 $ — Derivative Liabilities June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Current Gross amounts recognized $ 263 $ 7 $ 77 $ 18 $ 59 $ 1 $ 1 Gross amounts offset (15 ) (3 ) (13 ) (6 ) (7 ) — — Net amounts presented in Current Liabilities: Other $ 248 $ 4 $ 64 $ 12 $ 52 $ 1 $ 1 Noncurrent Gross amounts recognized $ 165 $ 82 $ 23 $ — $ 17 $ 7 $ — Gross amounts offset (5 ) — (5 ) — (4 ) — — Net amounts presented in Deferred Credits and Other Liabilities: Other $ 160 $ 82 $ 18 $ — $ 13 $ 7 $ —
Derivative Contracts with Contingent Credit Features	The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions. Amounts for Duke Energy Ohio and Duke Energy Indiana were not material. June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Aggregate fair value of derivatives in a net liability position $ 348 $ 89 $ 90 $ 18 $ 72 Fair value of collateral already posted — — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 348 89 90 18 72 December 31, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Aggregate fair value of derivatives in a net liability position $ 334 $ 45 $ 290 $ 93 $ 194 Fair value of collateral already posted 30 — 30 — 30 Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 304 45 260 93 164 The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative must be executed with the same counterparty under the same master netting arrangement. Amounts disclosed below represent the receivables related to the right to reclaim cash collateral under master netting arrangements. All receivables presented below were offset against net derivative positions on the Condensed Consolidated Balance Sheets. June 30, 2016 December 31, 2015 (in millions) Receivables Receivables Duke Energy $ — $ 30 Progress Energy — 30 Duke Energy Florida — 30

Investments in Debt and Equit35

Investments in Debt and Equity Securities (Tables)	6 Months Ended
	Jun. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 189 $ — $ — $ 179 Equity securities 1,869 78 3,834 1,823 58 3,590 Corporate debt securities 22 1 480 7 8 432 Municipal bonds 12 1 307 5 1 185 U.S. government bonds 38 — 1,038 11 5 1,254 Other debt securities 1 3 144 — 4 177 Total NDTF $ 1,942 $ 83 $ 5,992 $ 1,846 $ 76 $ 5,817 Other Investments Cash and cash equivalents $ — $ — $ 27 $ — $ — $ 29 Equity securities 34 1 98 32 1 95 Corporate debt securities 2 1 97 1 3 92 Municipal bonds 6 1 80 3 1 74 U.S. government bonds 2 — 47 — — 45 Other debt securities — 1 57 — 2 62 Total Other Investments (a) $ 44 $ 4 $ 406 $ 36 $ 7 $ 397 Total Investments $ 1,986 $ 87 $ 6,398 $ 1,882 $ 83 $ 6,214 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts are considered other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 88 Due after one through five years 660 Due after five through 10 years 511 Due after 10 years 991 Total $ 2,250
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 64 $ 28 $ 118 $ 130 Realized losses 42 17 92 31
Duke Energy Carolinas [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 66 $ — $ — $ 34 Equity securities 1,045 44 2,128 1,021 27 2,094 Corporate debt securities 13 1 309 3 5 292 Municipal bonds 2 — 42 1 — 33 U.S. government bonds 16 — 482 3 3 438 Other debt securities 1 3 136 — 4 147 Total NDTF $ 1,077 $ 48 $ 3,163 $ 1,028 $ 39 $ 3,038 Other Investments Other debt securities $ — $ 1 $ 3 $ — $ 1 $ 3 Total Other Investments (a) $ — $ 1 $ 3 $ — $ 1 $ 3 Total Investments $ 1,077 $ 49 $ 3,166 $ 1,028 $ 40 $ 3,041 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 6 Due after one through five years 198 Due after five through 10 years 235 Due after 10 years 533 Total $ 972
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 33 $ 17 $ 67 $ 107 Realized losses 19 11 56 23
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 123 $ — $ — $ 145 Equity securities 824 34 1,706 802 31 1,496 Corporate debt securities 9 — 171 4 3 140 Municipal bonds 10 1 265 4 1 152 U.S. government bonds 22 — 556 8 2 816 Other debt securities — — 8 — — 30 Total NDTF $ 865 $ 35 $ 2,829 $ 818 $ 37 $ 2,779 Other Investments Cash and cash equivalents $ — $ — $ 21 $ — $ — $ 18 Municipal bonds 4 — 47 3 — 45 Total Other Investments (a) $ 4 $ — $ 68 $ 3 $ — $ 63 Total Investments $ 869 $ 35 $ 2,897 $ 821 $ 37 $ 2,842 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 65 Due after one through five years 375 Due after five through 10 years 200 Due after 10 years 407 Total $ 1,047
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 31 $ 9 $ 50 $ 21 Realized losses 23 5 36 6
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 58 $ — $ — $ 110 Equity securities 614 28 1,379 596 25 1,178 Corporate debt securities 7 — 118 3 2 96 Municipal bonds 10 1 265 4 1 150 U.S. government bonds 14 — 281 6 2 486 Other debt securities — — 5 — — 18 Total NDTF $ 645 $ 29 $ 2,106 $ 609 $ 30 $ 2,038 Other Investments Cash and cash equivalents $ — $ — $ 1 $ — $ — $ 1 Total Other Investments (a) $ — $ — $ 1 $ — $ — $ 1 Total Investments $ 645 $ 29 $ 2,107 $ 609 $ 30 $ 2,039 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 14 Due after one through five years 191 Due after five through 10 years 154 Due after 10 years 310 Total $ 669
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 27 $ 8 $ 42 $ 17 Realized losses 20 4 31 5
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value NDTF Cash and cash equivalents $ — $ — $ 65 $ — $ — $ 35 Equity securities 210 6 327 206 6 318 Corporate debt securities 2 — 53 1 1 44 Municipal bonds — — — — — 2 U.S. government bonds 8 — 275 2 — 330 Other debt securities — — 3 — — 12 Total NDTF $ 220 $ 6 $ 723 $ 209 $ 7 $ 741 Other Investments Cash and cash equivalents $ — $ — $ 4 $ — $ — $ 6 Municipal bonds 4 — 47 3 — 45 Total Other Investments (a) $ 4 $ — $ 51 $ 3 $ — $ 51 Total Investments $ 224 $ 6 $ 774 $ 212 $ 7 $ 792 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 51 Due after one through five years 184 Due after five through 10 years 46 Due after 10 years 97 Total $ 378
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Realized gains $ 4 $ 1 $ 8 $ 4 Realized losses 3 1 5 1
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	The following table presents the estimated fair value of investments in available-for-sale securities. June 30, 2016 December 31, 2015 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses (b) Value Gains Losses (b) Value Other Investments Cash and cash equivalents $ — $ — $ — $ — $ — $ 2 Equity securities 28 — 73 27 — 71 Corporate debt securities — — 2 — — 2 Municipal bonds 1 1 29 — 1 26 Total Other Investments (a) $ 29 $ 1 $ 104 $ 27 $ 1 $ 101 Total Investments $ 29 $ 1 $ 104 $ 27 $ 1 $ 101 (a) These amounts are recorded in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets. (b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. (in millions) June 30, 2016 Due in one year or less $ 2 Due after one through five years 16 Due after five through 10 years 8 Due after 10 years 5 Total $ 31

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 3,834 $ 3,666 $ 1 $ — $ 167 Nuclear decommissioning trust fund debt securities 2,158 744 1,414 — — Other available-for-sale equity securities 98 98 — — — Other available-for-sale debt securities 308 74 230 4 — Derivative assets 108 2 72 34 — Total assets 6,506 4,584 1,717 38 167 Derivative liabilities (428 ) (1 ) (427 ) — — Net assets $ 6,078 $ 4,583 $ 1,290 $ 38 $ 167 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 3,590 $ 3,418 $ — $ — $ 172 Nuclear decommissioning trust fund debt securities 2,227 672 1,555 — — Other available-for-sale equity securities 95 95 — — — Other available-for-sale debt securities 302 75 222 5 — Derivative assets 26 — 16 10 — Total assets 6,240 4,260 1,793 15 172 Derivative liabilities (419 ) — (419 ) — — Net assets $ 5,821 $ 4,260 $ 1,374 $ 15 $ 172
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Operating Revenues. There was no change to the Level 3 balance during the three months ended June 30, 2015 . Three Months Ended June 30, 2016 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 4 $ 2 $ 6 Purchases, sales, issuances and settlements: Purchases — 34 34 Settlements — (6 ) (6 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 4 4 Balance at end of period $ 4 $ 34 $ 38 Six Months Ended June 30, 2016 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 5 $ 10 $ 15 Purchases, sales, issuances and settlements: Purchases — 34 34 Sales (1 ) — (1 ) Settlements — (13 ) (13 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 3 3 Balance at end of period $ 4 $ 34 $ 38 Six Months Ended June 30, 2015 (in millions) Investments Derivatives (net) Total Balance at beginning of period $ 5 $ (1 ) $ 4 Total pretax realized or unrealized gains included in earnings — 18 18 Purchases, sales, issuances and settlements: Purchases — 24 24 Settlements — (22 ) (22 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities — 4 4 Balance at end of period $ 5 $ 23 $ 28
Quantitative Information Table - Level 3	The following table includes quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. As of June 30, 2016 and December 31, 2015 , all Level 3 derivatives were financial transmission rights (FTRs). June 30, 2016 Fair Value of FTRs (in millions) Valuation Technique Unobservable Input Range Duke Energy $ 34 RTO auction pricing FTR price – per Megawatt-Hour (MWh) $ (1.64 ) - $ 8.64 Duke Energy Ohio 5 RTO auction pricing FTR price – per MWh 0.36 - 2.47 Duke Energy Indiana 29 RTO auction pricing FTR price – per MWh (1.64 ) - 8.64 December 31, 2015 Fair Value of FTRs (in millions) Valuation Technique Unobservable Input Range Duke Energy $ 10 RTO auction pricing FTR price – per MWh $ (0.74 ) - $ 7.29 Duke Energy Ohio 3 RTO auction pricing FTR price – per MWh 0.67 - 2.53 Duke Energy Indiana 7 RTO auction pricing FTR price – per MWh (0.74 ) - 7.29
Schedule Of Long Term Debt Fair Value [Table Text Block]	The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements. June 30, 2016 December 31, 2015 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy $ 42,273 $ 47,953 $ 39,569 $ 42,537 Duke Energy Carolinas 9,360 10,874 8,367 9,156 Progress Energy 15,486 16,715 14,464 15,856 Duke Energy Progress 6,565 7,344 6,518 6,757 Duke Energy Florida 5,540 5,226 4,266 4,908 Duke Energy Ohio 1,887 2,134 1,598 1,724 Duke Energy Indiana 3,937 4,717 3,768 4,219
Duke Energy Carolinas [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 2,128 $ 1,960 $ 1 $ — $ 167 Nuclear decommissioning trust fund debt securities 1,035 245 790 — — Other available-for-sale debt securities 3 — — 3 — Derivative assets 18 — 18 — — Total assets 3,184 2,205 809 3 167 Derivative liabilities (89 ) — (89 ) — — Net assets $ 3,095 $ 2,205 $ 720 $ 3 $ 167 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not categorized Nuclear decommissioning trust fund equity securities $ 2,094 $ 1,922 $ — $ — $ 172 Nuclear decommissioning trust fund debt securities 944 246 698 — — Other available-for-sale debt securities 3 — — 3 — Total assets 3,041 2,168 698 3 172 Derivative liabilities (45 ) — (45 ) — — Net assets $ 2,996 $ 2,168 $ 653 $ 3 $ 172
Progress Energy [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,706 $ 1,706 $ — Nuclear decommissioning trust fund debt securities 1,123 499 624 Other available-for-sale debt securities 68 21 47 Derivative assets 54 — 54 Total assets 2,951 2,226 725 Derivative liabilities (100 ) — (100 ) Net assets $ 2,851 $ 2,226 $ 625 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,496 $ 1,496 $ — Nuclear decommissioning trust fund debt securities 1,283 426 857 Other available-for-sale debt securities 63 18 45 Derivative assets 11 — 11 Total assets 2,853 1,940 913 Derivative liabilities (322 ) — (322 ) Net assets $ 2,531 $ 1,940 $ 591
Duke Energy Progress [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,379 $ 1,379 $ — Nuclear decommissioning trust fund debt securities and other 727 228 499 Other available-for-sale debt securities and other 1 1 — Derivative assets 25 — 25 Total assets 2,132 1,608 524 Derivative liabilities (18 ) — (18 ) Net assets $ 2,114 $ 1,608 $ 506 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 1,178 $ 1,178 $ — Nuclear decommissioning trust fund debt securities and other 860 141 719 Other available-for-sale debt securities and other 1 1 — Derivative assets 2 — 2 Total assets 2,041 1,320 721 Derivative liabilities (98 ) — (98 ) Net assets $ 1,943 $ 1,320 $ 623
Duke Energy Florida [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 327 $ 327 $ — Nuclear decommissioning trust fund debt securities and other 396 271 125 Other available-for-sale debt securities and other 51 4 47 Derivative assets 29 — 29 Total assets 803 602 201 Derivative liabilities (76 ) — (76 ) Net assets $ 727 $ 602 $ 125 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Nuclear decommissioning trust fund equity securities $ 318 $ 318 $ — Nuclear decommissioning trust fund debt securities and other 423 285 138 Other available-for-sale debt securities and other 51 6 45 Derivative assets 7 — 7 Total assets 799 609 190 Derivative liabilities (216 ) — (216 ) Net assets (liabilities) $ 583 $ 609 $ (26 )
Duke Energy Ohio [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which are disclosed in Note 9 . June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Derivative assets $ 5 $ — $ — $ 5 Derivative liabilities (8 ) — (8 ) — Net (liabilities) assets $ (3 ) $ — $ (8 ) $ 5 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Derivative assets $ 3 $ — $ — $ 3 Derivative liabilities (7 ) — (7 ) — Net (liabilities) assets $ (4 ) $ — $ (7 ) $ 3
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ — $ 7 Total pretax realized or unrealized gains included in earnings — (4 ) Purchases, sales, issuances and settlements: Purchases 5 — Sales — 5 Settlements — (3 ) Balance at end of period $ 5 $ 5 Derivatives (net) Six Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 3 $ (18 ) Total pretax realized or unrealized gains included in earnings — 21 Purchases, sales, issuances and settlements: Purchases 5 — Sales — 5 Settlements (2 ) (3 ) Total losses included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities (1 ) — Balance at end of period $ 5 $ 5
Duke Energy Indiana [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 9 . See Note 10 for additional information related to investments by major security type. June 30, 2016 (in millions) Total Fair Value Level 1 Level 2 Level 3 Other available-for-sale equity securities $ 73 $ 73 $ — $ — Other available-for-sale debt securities and other 31 — 31 — Derivative assets 31 2 — 29 Total assets 135 75 31 29 Derivative liabilities (1 ) (1 ) — — Net assets $ 134 $ 74 $ 31 $ 29 December 31, 2015 (in millions) Total Fair Value Level 1 Level 2 Level 3 Other available-for-sale equity securities $ 71 $ 71 $ — $ — Other available-for-sale debt securities and other 30 2 28 — Derivative assets 7 — — 7 Net assets $ 108 $ 73 $ 28 $ 7
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 2 $ 3 Purchases, sales, issuances and settlements: Purchases 29 18 Settlements (6 ) (10 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities 4 6 Balance at end of period $ 29 $ 17 Derivatives (net) Six Months Ended June 30, (in millions) 2016 2015 Balance at beginning of period $ 7 $ 14 Purchases, sales, issuances and settlements: Purchases 29 18 Settlements (11 ) (19 ) Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities 4 4 Balance at end of period $ 29 $ 17

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2016
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following table summarizes the amounts and expiration dates of the credit facilities described above. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt. Duke Energy Duke Energy Duke Energy Duke Energy Carolinas Progress Florida CRC DERF DEPR DEFR Expiration date December 2018 December 2018 February 2019 April 2019 Credit facility amount (in millions) $ 325 $ 425 $ 300 $ 225 Amounts borrowed at June 30, 2016 325 425 300 225 Amounts borrowed at December 31, 2015 325 425 254 225
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. June 30, 2016 Duke Energy Duke Duke Energy Energy (in millions) Renewables Other Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 39 $ 58 Investments in equity method unconsolidated affiliates 222 252 474 — — Total assets $ 222 $ 252 $ 474 $ 39 $ 58 Other current liabilities — 3 3 — — Deferred credits and other liabilities — 13 13 — — Total liabilities $ — $ 16 $ 16 $ — $ — Net assets $ 222 $ 236 $ 458 $ 39 $ 58 December 31, 2015 Duke Energy Duke Duke Energy Energy (in millions) Renewables Other Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 47 $ 60 Investments in equity method unconsolidated affiliates 235 152 387 — — Total assets $ 235 $ 152 $ 387 $ 47 $ 60 Other current liabilities — 3 3 — — Deferred credits and other liabilities — 14 14 — — Total liabilities $ — $ 17 $ 17 $ — $ — Net assets $ 235 $ 135 $ 370 $ 47 $ 60
Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	Key assumptions used in estimating fair value are detailed in the following table. Duke Energy Ohio Duke Energy Indiana 2016 2015 2016 2015 Anticipated credit loss ratio 0.5 % 0.6 % 0.3 % 0.3 % Discount rate 1.4 % 1.2 % 1.4 % 1.2 % Receivable turnover rate 13.2 % 12.9 % 10.6 % 10.6 % The following table shows the gross and net receivables sold. Duke Energy Ohio Duke Energy Indiana (in millions) June 30, 2016 December 31, 2015 June 30, 2016 December 31, 2015 Receivables sold $ 208 $ 233 $ 279 $ 260 Less: Retained interests 39 47 58 60 Net receivables sold $ 169 $ 186 $ 221 $ 200 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (in millions) 2016 2015 2016 2015 2016 2015 2016 2015 Sales Receivables sold $ 429 $ 425 $ 961 $ 1,069 $ 623 $ 637 $ 1,258 $ 1,353 Loss recognized on sale 2 2 5 5 2 2 5 5 Cash flows Cash proceeds from receivables sold 427 467 964 1,107 612 660 1,255 1,382 Collection fees received — 1 — 1 1 1 1 1 Return received on retained interests — 1 1 2 1 1 2 3
DEFPF [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets. (in millions) June 30, 2016 Regulatory Assets: Current $ 34 Current Assets: Other 7 Regulatory Assets and Deferred Debits: Regulatory assets 1,194 Current maturities of long-term debt 35 Long-Term Debt 1,243
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to renewables VIEs. (in millions) June 30, 2016 December 31, 2015 Current Assets: Other $ 223 $ 138 Property, plant and equipment, cost 2,578 2,015 Accumulated depreciation and amortization (376 ) (321 ) Current maturities of long-term debt 154 108 Long-Term Debt 866 968 Deferred Credits and Other Liabilities: Deferred income taxes 31 289 Deferred Credits and Other Liabilities: Other 277 33

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share	The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common stock outstanding to the diluted weighted average number of common shares outstanding. Three Months Ended June 30, Six Months Ended June 30, (in millions, except per-share amounts) 2016 2015 2016 2015 Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities $ 508 $ 600 $ 1,199 $ 1,372 Weighted average shares outstanding – basic 689 692 689 700 Equity Forwards 1 — — — Weighted average shares outstanding – diluted 690 692 689 700 Earnings per share from continuing operations attributable to Duke Energy common stockholders Basic $ 0.74 $ 0.87 $ 1.74 $ 1.96 Diluted $ 0.74 $ 0.87 $ 1.74 $ 1.96 Potentially dilutive items excluded from the calculation (a) 2 2 2 2 Dividends declared per common share $ 0.825 $ 0.795 $ 1.65 $ 1.59 (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule Of Stock-Based Compensation Expense	Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense, and stock-based compensation costs capitalized are included in the following table. Three Months Ended Six Months Ended June 30, June 30, (in millions) 2016 2015 2016 2015 Restricted stock unit awards $ 10 $ 11 $ 17 $ 20 Performance awards 5 8 10 13 Pretax stock-based compensation cost $ 15 $ 19 $ 27 $ 33 Tax benefit associated with stock-based compensation expense $ 5 $ 7 $ 9 $ 12 Stock-based compensation costs capitalized 1 1 2 2

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Employee Savings Plan Matching Contributions	The following table presents employer contributions made by Duke Energy and expensed by the Subsidiary Registrants. Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Three Months Ended June 30, 2016 $ 39 $ 13 $ 12 $ 8 $ 4 $ 1 $ 2 2015 37 13 12 8 3 1 2 Six Months Ended June 30, 2016 $ 91 $ 31 $ 27 $ 19 $ 8 $ 2 $ 4 2015 86 29 26 19 7 2 4
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan Contributions by Employer	The following table includes information related to the Duke Energy Registrants’ contributions to its U.S. qualified defined benefit pension plans. Duke Energy did not make any contributions to its U.S. qualified defined benefit pension plans during the six months ended June 30, 2016 . Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Contributions $ 132 $ 42 $ 42 $ 21 $ 21 $ 1 $ 9
Components of Net Periodic Pension Costs	The following tables include the components of net periodic pension costs for qualified pension plans. Three Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 37 $ 12 $ 10 $ 6 $ 5 $ 1 $ 2 Interest cost on projected benefit obligation 83 22 27 13 14 5 7 Expected return on plan assets (129 ) (36 ) (42 ) (20 ) (21 ) (7 ) (11 ) Amortization of actuarial loss 33 8 13 5 7 1 3 Amortization of prior service credit (4 ) (2 ) (1 ) (1 ) — — — Other 1 — — 1 — — — Net periodic pension costs $ 21 $ 4 $ 7 $ 4 $ 5 $ — $ 1 Three Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 39 $ 12 $ 11 $ 6 $ 5 $ 1 $ 2 Interest cost on projected benefit obligation 81 20 26 12 13 4 7 Expected return on plan assets (129 ) (33 ) (41 ) (21 ) (22 ) (7 ) (11 ) Amortization of actuarial loss 44 10 17 9 8 3 4 Amortization of prior service credit (3 ) (2 ) (1 ) (1 ) (1 ) — — Other 2 — — 1 1 — — Net periodic pension costs $ 34 $ 7 $ 12 $ 6 $ 4 $ 1 $ 2 Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 73 $ 24 $ 21 $ 12 $ 10 $ 2 $ 4 Interest cost on projected benefit obligation 166 43 53 25 28 10 14 Expected return on plan assets (258 ) (71 ) (84 ) (41 ) (42 ) (14 ) (21 ) Amortization of actuarial loss 66 16 27 11 14 2 6 Amortization of prior service credit (8 ) (4 ) (2 ) (1 ) — — — Other 4 1 1 1 — — — Net periodic pension costs $ 43 $ 9 $ 16 $ 7 $ 10 $ — $ 3 Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 79 $ 25 $ 22 $ 12 $ 10 $ 2 $ 5 Interest cost on projected benefit obligation 163 41 52 24 27 9 14 Expected return on plan assets (258 ) (69 ) (84 ) (41 ) (44 ) (13 ) (21 ) Amortization of actuarial loss 87 20 34 17 16 5 7 Amortization of prior service credit (7 ) (4 ) (2 ) (1 ) (1 ) — — Other 4 1 1 1 1 — — Net periodic pension costs $ 68 $ 14 $ 23 $ 12 $ 9 $ 3 $ 5
Non-Qualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	The following tables include the components of net periodic pension costs for non-qualified pension plans for registrants with non-qualified pension costs. Three Months Ended June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 3 1 1 1 1 Amortization of actuarial loss 2 — — — — Net periodic pension costs $ 6 $ 1 $ 1 $ 1 $ 1 Three Months Ended June 30, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 3 — 1 1 1 Amortization of actuarial loss 1 — 1 — — Net periodic pension costs $ 5 $ — $ 2 $ 1 $ 1 Six Months Ended June 30, 2016 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ — $ — $ — Interest cost on projected benefit obligation 7 1 2 1 1 Amortization of actuarial loss 4 — 1 — — Net periodic pension costs $ 12 $ 1 $ 3 $ 1 $ 1 Six Months Ended June 30, 2015 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Service cost $ 1 $ — $ 1 $ — $ — Interest cost on projected benefit obligation 7 1 2 1 1 Amortization of actuarial loss 3 — 1 — 1 Net periodic pension costs $ 11 $ 1 $ 4 $ 1 $ 2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	The following tables include the components of net periodic other post-retirement benefit costs. Three Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 1 $ — $ — $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 9 2 3 2 1 1 1 Expected return on plan assets (4 ) (2 ) — — — — (1 ) Amortization of actuarial loss (gain) 2 (1 ) 6 3 3 (1 ) — Amortization of prior service credit (36 ) (3 ) (25 ) (17 ) (9 ) — — Net periodic other post-retirement benefit costs $ (28 ) $ (4 ) $ (16 ) $ (12 ) $ (5 ) $ — $ — Three Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 1 $ 1 $ 1 $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 9 2 3 2 1 1 2 Expected return on plan assets (3 ) (2 ) — — — — — Amortization of actuarial loss (gain) 7 (1 ) 7 4 2 — (1 ) Amortization of prior service credit (35 ) (3 ) (25 ) (16 ) (7 ) — — Net periodic other post-retirement benefit costs $ (21 ) $ (3 ) $ (14 ) $ (10 ) $ (4 ) $ 1 $ 1 Six Months Ended June 30, 2016 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 2 $ — $ — $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 17 4 7 4 3 1 2 Expected return on plan assets (7 ) (4 ) — — — — (1 ) Amortization of actuarial loss (gain) 3 (2 ) 11 6 5 (1 ) (1 ) Amortization of prior service credit (71 ) (6 ) (51 ) (34 ) (18 ) — — Net periodic other post-retirement benefit costs $ (56 ) $ (8 ) $ (33 ) $ (24 ) $ (10 ) $ — $ — Six Months Ended June 30, 2015 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Service cost $ 3 $ 1 $ 1 $ — $ — $ — $ — Interest cost on accumulated post-retirement benefit obligation 18 4 7 4 3 1 2 Expected return on plan assets (6 ) (4 ) — — — — — Amortization of actuarial loss (gain) 13 (1 ) 14 9 5 — (1 ) Amortization of prior service credit (70 ) (7 ) (51 ) (33 ) (16 ) — — Net periodic other post-retirement benefit costs $ (42 ) $ (7 ) $ (29 ) $ (20 ) $ (8 ) $ 1 $ 1

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Summary of Effective Tax Rates	The effective tax rates from continuing operations for each of the Duke Energy Registrants are included in the following table. Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Duke Energy 31.8 % 35.6 % 27.2 % 33.6 % Duke Energy Carolinas 35.1 % 36.6 % 34.6 % 36.2 % Progress Energy 36.0 % 39.2 % 36.3 % 37.1 % Duke Energy Progress 35.5 % 40.6 % 35.4 % 36.0 % Duke Energy Florida 37.6 % 38.7 % 37.7 % 38.6 % Duke Energy Ohio 34.3 % 35.0 % 29.2 % 36.8 % Duke Energy Indiana 36.1 % 36.4 % 33.1 % 36.5 %

Organization and Basis of Pre42

Organization and Basis of Presentation Organization and Basis of Presentation (Narrative)(Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 192	$ 170

Organization and Basis of Pre43

Organization and Basis of Presentation (Schedule of Unbilled Revenues with Restricted Receivables) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 840	$ 748
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	330	283
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	209	172
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	104	102
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	105	70
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	2	3
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	38	31
Cinergy Receivables [Member] | Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	70	71
Cinergy Receivables [Member] | Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 109	$ 97

Organization and Basis of Pre44

Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 87	$ 97	$ 178	$ 197
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	7	9	15	18
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	50	57	96	106
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	4	4	9	8
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	46	53	87	98
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	22	23	51	55
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 8	$ 8	$ 16	$ 18

Acquisitions and Dispositions45

Acquisitions and Dispositions (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2016	Aug. 01, 2016	Feb. 22, 2016	Dec. 31, 2015
Significant Acquisitions and Disposals [Abstract]
Payments to acquire businesses				$ 29
Goodwill	$ 16,357		$ 16,357					$ 16,343
Asset Impairment Charges	195		198
Piedmont Natural Gas [Member]
Significant Acquisitions and Disposals [Abstract]
Forward starting interest rate swaps, notional	$ 1,400		$ 1,400
Shares offered	10.6		10.6
Bridge Facility	$ 4,900		$ 4,900
Bridge Facility, Remaining Borrowing Capacity	3,200		3,200
Acquirer Termination Fee	250		250
Acquiree Termination Fee	125		125
Duke Energy Progress [Member] | NCEMPA Generating Assets [Member]
Significant Acquisitions and Disposals [Abstract]
Payments to acquire businesses		$ 1,250
Acquisition adjustment, recorded within property, plant and equipment		$ 350
Duke Energy Ohio [Member]
Significant Acquisitions and Disposals [Abstract]
Goodwill	920		920					$ 920
Duke Energy Ohio [Member] | Midwest Generation Business [Member]
Significant Acquisitions and Disposals [Abstract]
Proceeds from sale of business				$ 2,800
International Energy [Member]
Significant Acquisitions and Disposals [Abstract]
Asset Impairment Charges			194
Segment Carrying Value	2,400		2,400
Currency Translation Adjustment	$ 589		$ 589
Term Loan Facility [Member]
Significant Acquisitions and Disposals [Abstract]
Bridge Facility							$ 1,000
Scenario, Forecast [Member] | Piedmont Natural Gas [Member]
Significant Acquisitions and Disposals [Abstract]
Payments to acquire businesses					$ 4,900
Long-term debt assumed					2,000
Goodwill					$ 3,500
Subsequent Event [Member] | Term Loan Facility [Member] | Piedmont Natural Gas [Member]
Significant Acquisitions and Disposals [Abstract]
Bridge Facility						$ 1,000

Acquisitions and Dispositions46

Acquisitions and Dispositions (Assets Held For Sale) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income From Discontinued Operations, net of tax	$ (1)	$ (57)	$ 2	$ 34
Duke Energy Ohio [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income From Discontinued Operations, net of tax		(65)	$ 2	25
Midwest Generation Business [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Operating Revenues				543
Loss on disposition		6		(37)
Income before income taxes		(80)		67
Income tax expense		(21)		30
Income From Discontinued Operations, net of tax		(59)		37
Midwest Generation Business [Member] | Duke Energy Ohio [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Operating Revenues				412
Loss on disposition				(44)
Income before income taxes		(88)		52
Income tax expense		(23)		27
Income From Discontinued Operations, net of tax		(65)		25
Other Disposal Groups [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income From Discontinued Operations, net of tax		2		(3)
Antitrust Lawsuit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Litigation Settlement, Expense		71		81
Antitrust Lawsuit [Member] | Duke Energy Ohio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Litigation Settlement, Expense		$ 71		$ 81

Business Segments (Narrative) (

Business Segments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenue, Net	$ 5,484	$ 5,589	$ 11,106	$ 11,654
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	510	600	1,201	1,373
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Revenue, Net	428	405	944	991
Commercial Portfolio [Member]
Segment Reporting Information [Line Items]
Revenue, Net	112	75	227	148
Commercial Portfolio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net	112	75	227	148
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	14	(30)	41	(23)
Commercial Portfolio [Member] | Duke Energy Ohio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net				14
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent				9
International Energy [Member]
Segment Reporting Information [Line Items]
Revenue, Net	270	287	516	560
International Energy [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net	270	287	516	560
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ (102)	$ 52	$ 21	$ 88
National Methanol Company [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%

Business Segments (Business Seg

Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating revenues	$ 5,484	$ 5,589	$ 11,106	$ 11,654
Segment income	510	600	1,201	1,373
Add back noncontrolling interests	3	4	8	7
(Loss) Income From Discontinued Operations, net of tax	(1)	(57)	2	34
Net income (loss)	512	547	1,211	1,414
Segment assets	122,654		122,654		$ 121,156
Loss Contingency, Loss in Period		46		53
Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,090	5,211	10,340	10,924
International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues	270	287	516	560
Asset Impairment Charges, net of tax	145		145
Commercial Portfolio [Member]
Segment Reporting Information [Line Items]
Operating revenues	112	75	227	148
Current State and Local Tax Expense (Benefit)		41		41
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	12	16	23	22
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,472	5,573	11,083	11,632
Operating Segments [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,099	5,220	10,358	10,943
Segment income	718	632	1,413	1,406
Segment assets	112,754		112,754
Operating Segments [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues	270	287	516	560
Segment income	(102)	52	21	88
Segment assets	3,131		3,131
Operating Segments [Member] | Commercial Portfolio [Member]
Segment Reporting Information [Line Items]
Operating revenues	112	75	227	148
Segment income	14	(30)	41	(23)
Segment assets	4,329		4,329
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,481	5,582	11,092	11,651
Segment income	630	654	1,475	1,471
Segment assets	120,214		120,214
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(26)	(27)	(53)	(58)
Segment income		(3)		(4)
Segment assets	180		180
Intersegment Eliminations [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	(9)	(9)	(18)	(19)
Intersegment Eliminations [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	(17)	(18)	(35)	(39)
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	(9)	(9)	(9)	(19)
Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	29	34	58	61
Segment income	(120)	(51)	(274)	(94)
Segment assets	2,260		2,260
Costs to achieve merger	69	$ 14	143	$ 27
Cost Savings Initiative, Net of tax	$ 15		$ 27

Business Segments (Schedule of

Business Segments (Schedule of Segment Reporting Information, by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Interest Expense	$ 500	$ 403	$ 1,011	$ 806
Segment income	510	600	1,201	1,373
Duke Energy Carolinas [Member]
Segment Reporting Information [Line Items]
Interest Expense	107	106	214	208
Duke Energy Carolinas [Member] | Other [Member]
Segment Reporting Information [Line Items]
Segment income	(17)	(10)	(34)	(18)
Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest Expense	160	166	320	334
Progress Energy [Member] | Other [Member]
Segment Reporting Information [Line Items]
Interest Expense	55	59	111	119
Segment income	(45)	(42)	(94)	(84)
Duke Energy Progress [Member]
Segment Reporting Information [Line Items]
Interest Expense	64	56	127	116
Duke Energy Progress [Member] | Other [Member]
Segment Reporting Information [Line Items]
Segment income	(8)	(4)	(16)	(8)
Duke Energy Florida [Member]
Segment Reporting Information [Line Items]
Interest Expense	40	50	81	99
Duke Energy Florida [Member] | Other [Member]
Segment Reporting Information [Line Items]
Segment income	(5)	(3)	(9)	(6)
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Interest Expense	21	18	41	38
Duke Energy Ohio [Member] | Other [Member]
Segment Reporting Information [Line Items]
Segment income	(10)	(6)	(19)	(8)
Duke Energy Indiana [Member]
Segment Reporting Information [Line Items]
Interest Expense	47	43	91	88
Duke Energy Indiana [Member] | Other [Member]
Segment Reporting Information [Line Items]
Segment income	$ (5)	$ (2)	$ (7)	$ (4)

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Dec. 31, 2015USD ($)	Mar. 31, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)MW	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	$ 11,373		$ 11,290		$ 11,290		$ 11,373
Electric Domestic Regulated Revenue			4,965	$ 5,090	10,018	$ 10,547
Payments to Acquire Businesses, Gross						29
Debt issuances			3,394		3,394
Property, Plant and Equipment, Net	75,709		77,329		$ 77,329		75,709
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW					1,471
Property, Plant and Equipment, Net			$ 295		$ 295
Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			40.00%		40.00%
Atlantic Coast Pipeline (ACP) [Member] | Dominion Resources [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			45.00%		45.00%
Atlantic Coast Pipeline (ACP) [Member] | Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			10.00%		10.00%
Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			7.50%		7.50%
Sabal Trail Transmission Pipeline [Member] | Spectra Energy [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			59.50%		59.50%
Sabal Trail Transmission Pipeline [Member] | NextEra [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			33.00%		33.00%
Western Carolinas Modernization Plan [Member]
Public Utilities, General Disclosures [Line Items]
Approved Appeal Bond			$ 98		$ 98
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	2,766		2,856		2,856		2,766
Debt issuances			1,000		1,000
Property, Plant and Equipment, Net	25,877		26,405		$ 26,405		25,877
Duke Energy Carolinas [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission					10.20%
Duke Energy Carolinas [Member] | FERC Complaint [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					8.49%
Duke Energy Carolinas [Member] | William States Lee Combined Cycle Facility [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC			$ 600		$ 600
Duke Energy Carolinas [Member] | William States Lee Combined Cycle Facility [Member] | NCEMC [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			13.00%		13.00%
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	5,435		$ 5,298		$ 5,298		5,435
Property, Plant and Equipment, Net	28,347		29,139		$ 29,139		28,347
Progress Energy [Member] | Crystal River Units 1 and 2 [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW					873
Property, Plant and Equipment, Net			126		$ 126
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	2,710		2,744		2,744		2,710
Property, Plant and Equipment, Net	17,720		17,927		17,927		17,720
Duke Energy Progress [Member] | Western Carolinas Modernization Plan [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			1,100		$ 1,100
Duke Energy Progress [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission					10.80%
Duke Energy Progress [Member] | FERC Complaint [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					8.49%
Duke Energy Progress [Member] | 2016 South Carolina Rate Case [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					10.75%
Public Utilities, Requested Rate Increase (Decrease), Percentage					14.50%
Public Utilities, Requested Rate Increase (Decrease), Amount					$ 79
Duke Energy Progress [Member] | Asheville Plant [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW					376
Property, Plant and Equipment, Net	548		506		$ 506		548
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	2,725		2,553		2,553		2,725
Debt issuances			1,294		1,294
Property, Plant and Equipment, Net	10,623		11,208		11,208		10,623
Duke Energy Florida [Member] | Hines Chiller Uprate Project [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			150		150
Duke Energy Florida [Member] | Hines Chiller Uprate Project Phase 1[Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount					16
Duke Energy Florida [Member] | Hines Chiller Uprate Project Phase 2 [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount					3
Duke Energy Florida [Member] | Osprey Energy Center Acquisition [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount					$ 48
Duke Energy Florida [Member] | Osprey Energy Center Acquisition [Member] | Scenario, Forecast [Member]
Public Utilities, General Disclosures [Line Items]
Payments to Acquire Businesses, Gross		$ 166
Duke Energy Florida [Member] | Crystal River Units 1 and 2 [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW					873
Property, Plant and Equipment, Net			126		$ 126
Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Asset, Amortization Period					20 years
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	497		472		$ 472		497
Electric Domestic Regulated Revenue			323	$ 299	663	$ 638
Debt issuances			250		250
Property, Plant and Equipment, Net	5,243		5,370		5,370		5,243
Duke Energy Ohio [Member] | Energy Efficiency and Peak Demand Reduction Program [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Electric Domestic Regulated Revenue	20
Duke Energy Ohio [Member] | Advanced Metering Infrastructure Project [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			10		10
Estimated capital cost			49		49
Duke Energy Ohio [Member] | Accelerated Natural Gas Service Line Replacement Rider [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			320		320
Duke Energy Ohio [Member] | Regional Transmission Organization [Member]
Public Utilities, General Disclosures [Line Items]
Exit obligation	92		91		91		92
Regulatory Assets, Noncurrent	72		$ 72		$ 72		72
Duke Energy Ohio [Member] | RTO Realignment [Member]
Public Utilities, General Disclosures [Line Items]
Approved MVP Proposals			17		17
MISO estimate of Duke Energy Ohio's MVP obligation					$ 2,700
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	716		$ 825		825		716
Debt issuances			500		500
Property, Plant and Equipment, Net	$ 9,523		9,551		9,551		9,523
Duke Energy Indiana [Member] | Coal Combustion Residual Plan [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			380		$ 380
Federal Mandate Costs Recovered Through Tracker Mechanism					80.00%
Federally Mandated Costs Recovered In Future Rate Case					20.00%
Duke Energy Indiana [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission					12.38%
Duke Energy Indiana [Member] | FERC Transmission Rates [Member] | Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission					0.50%
Duke Energy Indiana [Member] | FERC Complaint 1 [Member] | Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					10.32%
Duke Energy Indiana [Member] | FERC Complaint 2 [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					8.67%
Duke Energy Indiana [Member] | FERC Complaint 2 [Member] | Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					9.70%
Duke Energy Indiana [Member] | Grid Infrastructure Improvement Plan [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			1,900		$ 1,900
Duke Energy Indiana [Member] | Revised Grid Infrastructure Improvement Plan [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Return on Equity, Percentage					10.00%
Estimated capital cost			1,800		$ 1,800
Public Utilities, Requested Rate Increase (Decrease), Amount					1,400
Duke Energy Indiana [Member] | Edwardsport Igcc Plant [Member] | IGCC Rider Proceeding [Member] | IURC [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount					87.5
Legal Fees					$ 5.5
Utilities Operating Expense, Other							$ 93
Regulatory Asset, Amortization Period					8 years
Regulatory Assets			175		$ 175
Minimum [Member] | Duke Energy Ohio [Member] | Natural Gas Pipeline Extension [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			100		100
Maximum [Member] | Duke Energy Carolinas [Member] | Advanced Metering Infrastructure Deferral [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			45		45
Maximum [Member] | Duke Energy Ohio [Member] | Natural Gas Pipeline Extension [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			150		150
DEFPF [Member] | Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			1,194		1,194
Debt issuances			1,294		1,294
DEFPF [Member] | Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Public Utilities, General Disclosures [Line Items]
Proceeds from Issuance of Debt					1,287
Debt issuances			$ 1,294		$ 1,294

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)MW	Dec. 31, 2015USD ($)
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 77,329	$ 75,709
Generation Facilities To Be Retired Net	$ 598	548
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,471
Remaining net book value (in millions)	$ 295
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	26,405	25,877
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	29,139	28,347
Generation Facilities To Be Retired Net	$ 506	548
Progress Energy [Member] | Generation Facilities To Be Retired [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 126
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	17,927	17,720
Generation Facilities To Be Retired Net	506	548
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 11,208	10,623
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 126
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	5,370	5,243
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	9,551	$ 9,523
Generation Facilities To Be Retired Net	93
Duke Energy Indiana [Member] | Wabash River Unit 6 [Member]
Public Utilities, General Disclosures [Line Items]
Generation Facilities To Be Retired Net	$ 93
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member] | Wabash River Unit 6 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	318
Remaining net book value (in millions)	$ 34
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member] | Gallagher Units 2 and 4 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Remaining net book value (in millions)	$ 135

Commitments and Contingencies52

Commitments and Contingencies (Narrative) (Details) $ in Millions	Feb. 08, 2016USD ($)	Mar. 10, 2015USD ($)	Feb. 02, 2014Tgal	Aug. 10, 2011	Aug. 09, 2011	Mar. 31, 2014USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)plantClaimsbasin	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)	Aug. 18, 2014gal
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								$ 110		$ 166
Charge for settlement agreement							$ 46		$ 53
Coal Ash Act Intermediate Ranking [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Ash Basins | basin								12
Number of Plants with Ash Basins | plant								4
Coal Ash Act Low Ranking [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Ash Basins | basin								4
Number of Plants with Ash Basins | plant								3
Coal Ash Act Low to Intermediate Ranking [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Ash Basins | basin								9
Number of Plants with Ash Basins | plant								6
NCDEQ State Enforcement Actions [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Plants with No Disputed Facts | plant								7
Number of Plants with Ash Basins | plant								14
Potential Groundwater Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Plants with Ash Basins | plant								14
Brazil Expansion Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Obligation to expand installed generation capacity, percent				15.00%	15.00%
Antitrust Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense							71		81
Duke Energy Carolinas [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								$ 14		11
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member]
Valuation and Qualifying Accounts [Abstract]
Civil Penalty Assessed	$ 6.8
Duke Energy Carolinas [Member] | Groundwater Violation [Member]
Valuation and Qualifying Accounts [Abstract]
Charge for settlement agreement								1
Duke Energy Carolinas [Member] | Asbestos Issue [Member]
Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves								515		536
Reinsurance retention policy, excess retention, amount reinsured								847
Probable insurance recoveries								$ 600		599
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Non Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | Claims								89
Asbestos-related injuries and damages reserves								$ 24
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | Claims								83
Asbestos-related injuries and damages reserves								$ 15
Duke Energy Carolinas [Member] | Minimum [Member] | North Carolina Ash Basins [Member] | Dan River [Member]
Valuation and Qualifying Accounts [Abstract]
Coal ash released, in tons | T			30,000
Basin water released, in gallons | gal			24,000,000
Duke Energy Carolinas [Member] | Maximum [Member] | North Carolina Ash Basins [Member] | Dan River [Member]
Valuation and Qualifying Accounts [Abstract]
Coal ash released, in tons | T			39,000
Basin water released, in gallons | gal			27,000,000
Progress Energy [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								52		54
Duke Energy Progress [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								6		6
Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | L V Sutton Plant [Member]
Valuation and Qualifying Accounts [Abstract]
Civil Penalty Assessed		$ 25
Duke Energy Progress [Member] | Groundwater Violation [Member]
Valuation and Qualifying Accounts [Abstract]
Charge for settlement agreement								6
Duke Energy Progress [Member] | Groundwater Violation [Member] | L V Sutton Plant [Member]
Valuation and Qualifying Accounts [Abstract]
Civil Penalty Assessed		$ 25
Duke Energy Florida [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								30		31
Duke Energy Florida [Member] | Westinghouse Electric Company Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount								54
Loss contingency, damages sought, value						$ 510
Duke Energy Ohio [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual								$ 4		80
Duke Energy Ohio [Member] | W.C. Beckjord Station [Member]
Valuation and Qualifying Accounts [Abstract]
Gallons of Fuel Released | gal											9,000
Duke Energy Ohio [Member] | Antitrust Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement Amount										$ 81
Litigation Settlement, Expense							$ 71		$ 81

Commitments and Contingencies53

Commitments and Contingencies (Schedule of Environmental Loss Contingencies) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	$ 75
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	97	$ 97
Provisions/adjustments	28	5
Cash reductions	(7)	(4)
Ending balance	118	98
Duke Energy Carolinas [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	22
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	10	10
Provisions/adjustments	3
Cash reductions	(2)
Ending balance	11	10
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	17	17
Provisions/adjustments	4	2
Cash reductions	(4)	(2)
Ending balance	17	17
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	3	5
Provisions/adjustments	1
Cash reductions	(1)	(1)
Ending balance	3	4
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	14	12
Provisions/adjustments	3	2
Cash reductions	(3)	(1)
Ending balance	14	13
Duke Energy Ohio [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	42
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	54	54
Provisions/adjustments	1	1
Cash reductions	(1)	(1)
Ending balance	54	54
Duke Energy Indiana [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	7
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	12	10
Provisions/adjustments	21	3
Cash reductions	(1)	(1)
Ending balance	$ 32	$ 12

Commitments and Contingencies54

Commitments and Contingencies (Schedule of Legal Reserves) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Reserves for legal matters	$ 110	$ 166
Duke Energy Carolinas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	14	11
Progress Energy [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	52	54
Duke Energy Progress [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	6	6
Duke Energy Florida [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	30	31
Duke Energy Ohio [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	$ 4	$ 80

Debt and Credit Facilities Debt

Debt and Credit Facilities Debt and Credit Facilities (Narrative) (Details) - USD ($) $ in Millions	Feb. 22, 2016	Sep. 30, 2016	Jun. 30, 2016	Aug. 03, 2016	Aug. 01, 2016
Debt Instrument [Line Items]
Debt issuances			$ 3,394
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Facility size			4,900
Available capacity			3,200
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size			7,500
Available capacity			5,134
February 2016 Term Loan Facility [Member]
Debt Instrument [Line Items]
Facility size	$ 1,000
Debt Instrument, Term	6 months
Amount outstanding at period end			100
February 2016 Term Loan Facility [Member] | Subsequent Event [Member] | Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Facility size					$ 1,000
August 2016 Term Loan Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Facility size					1,500
Facility size at period end					100
Available capacity					1,400
Debt Instrument, Term		10 months
Expiration Period (in days)		90 days
August 2016 Term Loan Facility [Member] | Subsequent Event [Member] | Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Facility size					$ 1,000
Solar Facilities Financing [Member] | Subsequent Event [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuances				$ 333
Solar Facilities Financing [Member] | Subsequent Event [Member] | Secured Debt [Member] | 1.75% Secured Debt Maturing June 2034 [Member]
Debt Instrument [Line Items]
Debt issuances				$ 228
Interest rate				1.75%
Debt Instrument, Interest Rate, Increase (Decrease)		0.125%
Solar Facilities Financing [Member] | Subsequent Event [Member] | Secured Debt [Member] | 1.75% Secured Debt Maturing June 2020 [Member]
Debt Instrument [Line Items]
Debt issuances				$ 105
Interest rate				1.75%
Debt Instrument, Interest Rate, Increase (Decrease)		0.125%
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size			1,000
Available capacity			589
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances			1,000
Duke Energy Carolinas [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size			800
Available capacity			211
USDOJ [Member] | Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required			250
USDOJ [Member] | Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required			$ 250
Swap [Member] | Solar Facilities Financing [Member] | Subsequent Event [Member] | Secured Debt [Member] | 1.75% Secured Debt Maturing June 2034 [Member]
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate				1.81%
Swap [Member] | Solar Facilities Financing [Member] | Subsequent Event [Member] | Secured Debt [Member] | 1.75% Secured Debt Maturing June 2020 [Member]
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate				1.38%

Debt and Credit Facilities (Sum

Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Debt Instrument [Line Items]
Debt issuances		$ 3,394
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances		350
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances		1,000
Distributions to parent		1,200	$ 100
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Debt issuances		1,294
Distributions to parent		649
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances		250
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Debt issuances		500
Distributions to parent		149
Unsecured Debt [Member] | April 2016 2.875% Unsecured Note Maturing April 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 350
Interest rate		2.875%
Unsecured Debt [Member] | Parent Company [Member] | April 2016 2.875% Unsecured Note Maturing April 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 350
Interest rate		2.875%
First Mortgage [Member] | March 2016 2.500% First Mortgage Bond Maturing March 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		2.50%
First Mortgage [Member] | March 2016 3.875% First Mortgage Bond Maturing March 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.875%
First Mortgage [Member] | May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.75%
Repayments of Debt		$ 325
First Mortgage [Member] | June 2016 3.700% First Mortgage Bond Maturing June 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		3.70%
First Mortgage [Member] | Duke Energy Carolinas [Member] | March 2016 2.500% First Mortgage Bond Maturing March 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		2.50%
First Mortgage [Member] | Duke Energy Carolinas [Member] | March 2016 3.875% First Mortgage Bond Maturing March 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.875%
First Mortgage [Member] | Duke Energy Ohio [Member] | June 2016 3.700% First Mortgage Bond Maturing June 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		3.70%
First Mortgage [Member] | Duke Energy Indiana [Member] | May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.75%
Repayments of Debt		$ 325
Secured Debt [Member] | June 2016 1.196% Secured Debt Maturing March 2020 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 183
Interest rate		1.196%
Secured Debt [Member] | June 2016 1.731% Secured Debt Maturing September 2022 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 150
Interest rate		1.731%
Secured Debt [Member] | June 2016 2.538% Secured Debt Maturing September 2029 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 436
Interest rate		2.538%
Secured Debt [Member] | June 2016 2.858% Secured Debt Maturing March 2033 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		2.858%
Secured Debt [Member] | June 2016 3.112% Secured Debt Maturing September 2036 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 275
Interest rate		3.112%
Secured Debt [Member] | Duke Energy Florida [Member] | June 2016 1.196% Secured Debt Maturing March 2020 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 183
Interest rate		1.196%
Distributions to parent		$ 649
Secured Debt [Member] | Duke Energy Florida [Member] | June 2016 1.731% Secured Debt Maturing September 2022 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 150
Interest rate		1.731%
Distributions to parent		$ 649
Secured Debt [Member] | Duke Energy Florida [Member] | June 2016 2.538% Secured Debt Maturing September 2029 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 436
Interest rate		2.538%
Distributions to parent		$ 649
Secured Debt [Member] | Duke Energy Florida [Member] | June 2016 2.858% Secured Debt Maturing March 2033 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		2.858%
Distributions to parent		$ 649
Secured Debt [Member] | Duke Energy Florida [Member] | June 2016 3.112% Secured Debt Maturing September 2036 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 275
Interest rate		3.112%
Distributions to parent		$ 649
Subsequent Event [Member] | First Mortgage [Member] | May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 150
Subsequent Event [Member] | First Mortgage [Member] | Duke Energy Indiana [Member] | May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 150

Debt and Credit Facilities (S57

Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt)(Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 2,342	$ 2,074
Unsecured Debt [Member] | 15.530% Unsecured Debt Maturing May 2017 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 56
Interest rate	15.53%
Secured Debt [Member] | 2.075% Secured Debt Maturing June 2017 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 45
Interest rate	2.075%
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 420
Parent Company [Member] | Unsecured Debt [Member] | 2.150% Unsecured Debt Maturing November 2016 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 500
Interest rate	2.15%
Parent Company [Member] | Unsecured Debt [Member] | 1.009% Unsecured Debt Maturing April 2017 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 400
Interest rate	1.009%
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 468	356
Duke Energy Carolinas [Member] | First Mortgage Bonds [Member] | 1.750% First Mortgage Bonds Maturing December 2016 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 350
Interest rate	1.75%
Duke Energy Carolinas [Member] | Tax Exempt Bonds [Member] | 3.600% Tax-exempt Bonds Maturing February 2017[Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 77
Interest rate	3.60%
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 252	2
Duke Energy Progress [Member] | First Mortgage Bonds [Member] | 0.880% First Mortgage Bonds Maturing March 2017 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 250
Interest rate	0.88%
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 48	13
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	54	106
Duke Energy Ohio [Member] | Tax Exempt Bonds [Member] | 1.280% Tax-exempt Bonds Maturing August 2027 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 50
Interest rate	1.28%
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 221	$ 547
Duke Energy Indiana [Member] | First Mortgage Bonds [Member] | 0.979% First Mortgage Bonds Maturing July 2016 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 150
Interest rate	0.979%
Duke Energy Indiana [Member] | Tax Exempt Bonds [Member] | 1.092% Tax-exempt Bonds Maturing May 2035 [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 44
Interest rate	1.092%

Debt and Credit Facilities (Sch

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Revolving Credit Facility [Member] $ in Millions	Jun. 30, 2016USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 7,500
Commercial paper	(1,673)
Outstanding letters of credit	(77)
Tax exempt bonds	(116)
Coal ash set-aside	(500)
Available capacity	5,134
Parent Company [Member]
Line of Credit Facility [Line Items]
Facility size	3,475
Commercial paper	(992)
Outstanding letters of credit	(70)
Available capacity	2,413
Duke Energy Carolinas [Member]
Line of Credit Facility [Line Items]
Facility size	800
Commercial paper	(300)
Outstanding letters of credit	(4)
Tax exempt bonds	(35)
Coal ash set-aside	(250)
Available capacity	211
Duke Energy Progress [Member]
Line of Credit Facility [Line Items]
Facility size	1,000
Commercial paper	(159)
Outstanding letters of credit	(2)
Coal ash set-aside	(250)
Available capacity	589
Duke Energy Florida [Member]
Line of Credit Facility [Line Items]
Facility size	1,200
Commercial paper	(47)
Outstanding letters of credit	(1)
Available capacity	1,152
Duke Energy Ohio [Member]
Line of Credit Facility [Line Items]
Facility size	425
Commercial paper	(25)
Available capacity	400
Duke Energy Indiana [Member]
Line of Credit Facility [Line Items]
Facility size	600
Commercial paper	(150)
Tax exempt bonds	(81)
Available capacity	369
Proceeds Loaned To Subsidiary Registrants [Member] | Parent Company [Member]
Line of Credit Facility [Line Items]
Commercial paper	$ (625)

Goodwill and Intangible Asset59

Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill	$ 16,357	$ 16,343
Foreign exchange changes	14
Regulated Utilities [Member]
Goodwill [Roll Forward]
Goodwill	15,950	15,950
International [Member]
Goodwill [Roll Forward]
Goodwill	285	271
Foreign exchange changes	14
Commercial Portfolio [Member]
Goodwill [Roll Forward]
Goodwill	122	122
Duke Energy Ohio [Member]
Goodwill [Roll Forward]
Goodwill	920	920
Accumulated impairment charges	$ 216	$ 216

Related Party Transactions (Oth

Related Party Transactions (Other Revenue and Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Duke Energy Carolinas [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 199	$ 202	$ 416	$ 421
Duke Energy Carolinas [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	6	11	12
Duke Energy Carolinas [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	2	14	11	40
Related party transaction, expenses from transactions with related party	50	38	91	95
Progress Energy [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	160	172	334	339
Progress Energy [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	9	9	17	19
Progress Energy [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	50	38	91	95
Related party transaction, expenses from transactions with related party	2	14	11	40
Duke Energy Progress [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	89	93	189	194
Duke Energy Progress [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	4	7	8
Duke Energy Progress [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	50	38	91	95
Related party transaction, expenses from transactions with related party	2	14	11	40
Duke Energy Florida [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	71	79	145	145
Duke Energy Florida [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	5	10	11
Duke Energy Ohio [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	87	103	172	188
Duke Energy Ohio [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1	2	4
Duke Energy Indiana [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	89	83	183	172
Duke Energy Indiana [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 2	$ 2	$ 4	$ 4

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - Duke Energy Ohio [Member] - USD ($) $ in Millions	Dec. 31, 2015	Apr. 01, 2015
Related Party Transaction [Line Items]
Intercompany loan payable	$ 103
DECAM [Member]
Related Party Transaction [Line Items]
Intercompany loan payable		$ 294

Related Party Transactions Rela

Related Party Transactions Related Party Transactions (Intercompany Income Taxes) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Duke Energy Carolinas [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	$ 71	$ 107
Due to Related Parties, Current	173	229
Duke Energy Carolinas [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	10	122
Progress Energy [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	11	375
Due to Related Parties, Current	232	311
Progress Energy [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	90	120
Duke Energy Progress [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	9	16
Due to Related Parties, Current	134	190
Duke Energy Progress [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current		104
Due to Related Parties, Current	11
Duke Energy Florida [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	3	84
Due to Related Parties, Current	100	116
Duke Energy Florida [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due to Related Parties, Current	48	96
Duke Energy Ohio [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	35	84
Due to Related Parties, Current	76	53
Duke Energy Ohio [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	15	54
Duke Energy Indiana [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	60	71
Due to Related Parties, Current	87	83
Duke Energy Indiana [Member] | Income Taxes [Member]
Income Tax Disclosure [Line Items]
Due from Related Parties, Current	$ 6
Due to Related Parties, Current		$ 47

Derivatives and Hedging (Notion

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Bcf in Millions, $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2016USD ($)	Jun. 30, 2016USD ($)GWhBcf	Dec. 31, 2015USD ($)GWhBcf
Derivative [Line Items]
Undesignated Commodity Contracts Latest Expiration Year		2,020
Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh		7	70
Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Bcf		418	398
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 2,990	$ 2,990	$ 2,527
Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	663	663	700
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	2,327	2,327	1,827
Variable Interest Entity, Primary Beneficiary [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	463	463	$ 497
Piedmont Natural Gas [Member]
Derivative [Line Items]
Notional amount	1,400	1,400
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	1,400	1,400
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	75	$ 168
Duke Energy Carolinas [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Bcf		80	66
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	400	$ 400	$ 400
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	400	$ 400	$ 400
Progress Energy [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Bcf		338	332
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	500	$ 500	$ 500
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	500	$ 500	$ 500
Duke Energy Progress [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Bcf		124	117
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	$ 250	$ 250
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	$ 250	$ 250
Duke Energy Florida [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Bcf		214	215
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	$ 250	$ 250
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	250	$ 250
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh			34
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	27	27	$ 27
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 27	$ 27	$ 27
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh		7	36

Derivatives and Hedging (Locati

Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 108	$ 26
Location and fair value amounts of derivatives (Liability)	428	419
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	67	18
Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	41	8
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	263	271
Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	165	148
Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	92	16
Location and fair value amounts of derivatives (Liability)	107	356
Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	16	10
Location and fair value amounts of derivatives (Liability)	321	63
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	11
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	52	33
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	64	12
Location and fair value amounts of derivatives (Liability)	84	256
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	28	4
Location and fair value amounts of derivatives (Liability)	23	100
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	6
Location and fair value amounts of derivatives (Liability)	170	4
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	13
Location and fair value amounts of derivatives (Liability)	90	15
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18
Location and fair value amounts of derivatives (Liability)	89	45
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8
Duke Energy Carolinas [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	32
Duke Energy Carolinas [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	82	13
Duke Energy Carolinas [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18
Location and fair value amounts of derivatives (Liability)	7	40
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	82	5
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8
Location and fair value amounts of derivatives (Liability)	7	32
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10
Location and fair value amounts of derivatives (Liability)		8
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	82	5
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	54	11
Location and fair value amounts of derivatives (Liability)	100	322
Progress Energy [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	23	7
Progress Energy [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	4
Progress Energy [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	77	225
Progress Energy [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	23	97
Progress Energy [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	38	5
Location and fair value amounts of derivatives (Liability)	100	314
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	16	6
Location and fair value amounts of derivatives (Liability)		8
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	1
Location and fair value amounts of derivatives (Liability)	77	222
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18	4
Location and fair value amounts of derivatives (Liability)	23	92
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	6
Location and fair value amounts of derivatives (Liability)		3
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	13
Location and fair value amounts of derivatives (Liability)		5
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	25	2
Location and fair value amounts of derivatives (Liability)	18	98
Duke Energy Progress [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	2
Duke Energy Progress [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	16
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	18	77
Duke Energy Progress [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		21
Duke Energy Progress [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18
Location and fair value amounts of derivatives (Liability)	18	93
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	2
Location and fair value amounts of derivatives (Liability)		5
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8
Location and fair value amounts of derivatives (Liability)	18	77
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10
Location and fair value amounts of derivatives (Liability)		16
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6
Location and fair value amounts of derivatives (Liability)		5
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	29	7
Location and fair value amounts of derivatives (Liability)	76	216
Duke Energy Florida [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	3
Duke Energy Florida [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	4
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	59	145
Duke Energy Florida [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	17	71
Duke Energy Florida [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	5
Location and fair value amounts of derivatives (Liability)	76	216
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	12	1
Location and fair value amounts of derivatives (Liability)	59	145
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8	4
Location and fair value amounts of derivatives (Liability)	17	71
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	5	3
Location and fair value amounts of derivatives (Liability)	8	7
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	5	3
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	6
Duke Energy Ohio [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	5	3
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	7
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	5	3
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	6
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	7
Location and fair value amounts of derivatives (Liability)	1
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	7
Duke Energy Indiana [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Duke Energy Indiana [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	7
Location and fair value amounts of derivatives (Liability)	1
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	$ 7
Location and fair value amounts of derivatives (Liability)	1
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	$ 168

Derivatives and Hedging (Schedu

Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 108	$ 26
Net amounts recognized on the Condensed Consolidated Balance Sheet	108	26
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	428	419
Net amounts recognized on the Condensed Consolidated Balance Sheet	428	419
Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	67	18
Gross amounts offset	(15)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	52	15
Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	41	8
Gross amounts offset	(5)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	36	4
Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	263	271
Gross amounts offset	(15)	(22)
Net amounts recognized on the Condensed Consolidated Balance Sheet	248	249
Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	165	148
Gross amounts offset	(5)	(16)
Net amounts recognized on the Condensed Consolidated Balance Sheet	160	132
Duke Energy Carolinas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	18
Net amounts recognized on the Condensed Consolidated Balance Sheet	18
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	89	45
Net amounts recognized on the Condensed Consolidated Balance Sheet	89	45
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	8
Gross amounts offset	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	5
Duke Energy Carolinas [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	10
Net amounts recognized on the Condensed Consolidated Balance Sheet	10
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	32
Gross amounts offset	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	32
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	82	13
Net amounts recognized on the Condensed Consolidated Balance Sheet	82	13
Progress Energy [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	54	11
Net amounts recognized on the Condensed Consolidated Balance Sheet	54	11
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	100	322
Net amounts recognized on the Condensed Consolidated Balance Sheet	100	322
Progress Energy [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	23	7
Gross amounts offset	(13)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	10	5
Progress Energy [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	31	4
Gross amounts offset	(5)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	26
Progress Energy [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	77	225
Gross amounts offset	(13)	(21)
Net amounts recognized on the Condensed Consolidated Balance Sheet	64	204
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	23	97
Gross amounts offset	(5)	(15)
Net amounts recognized on the Condensed Consolidated Balance Sheet	18	82
Duke Energy Progress [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	25	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	25	2
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	18	98
Net amounts recognized on the Condensed Consolidated Balance Sheet	18	98
Duke Energy Progress [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	9	2
Gross amounts offset	(6)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	2
Duke Energy Progress [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	16
Net amounts recognized on the Condensed Consolidated Balance Sheet	16
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	18	77
Gross amounts offset	(6)	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	12	76
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		21
Net amounts recognized on the Condensed Consolidated Balance Sheet		21
Duke Energy Florida [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	29	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	7
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	76	216
Net amounts recognized on the Condensed Consolidated Balance Sheet	76	216
Duke Energy Florida [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	14	3
Gross amounts offset	(7)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	1
Duke Energy Florida [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	15	4
Gross amounts offset	(4)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	11
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	59	145
Gross amounts offset	(7)	(20)
Net amounts recognized on the Condensed Consolidated Balance Sheet	52	125
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	17	71
Gross amounts offset	(4)	(15)
Net amounts recognized on the Condensed Consolidated Balance Sheet	13	56
Duke Energy Ohio [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	5	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	5	3
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	8	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	8	7
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	5	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	5	3
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	6
Duke Energy Indiana [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	31	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	31	7
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	(1)
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	31	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	31	$ 7
Duke Energy Indiana [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 1

Derivatives and Hedging (Deriva

Derivatives and Hedging (Derivative Instruments with Credit-Risk Related Contingent Features and Cash Collateral) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	$ 348	$ 334
Fair value of collateral already posted		30
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	348	304
Information Regarding Cash Collateral Under Master Netting Arrangements
Amount of right to receive cash collateral, offset against derivative liability		30
Duke Energy Carolinas [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	89	45
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	89	45
Progress Energy [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	90	290
Fair value of collateral already posted		30
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	90	260
Information Regarding Cash Collateral Under Master Netting Arrangements
Amount of right to receive cash collateral, offset against derivative liability		30
Duke Energy Progress [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	18	93
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	18	93
Duke Energy Florida [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	72	194
Fair value of collateral already posted		30
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	$ 72	164
Information Regarding Cash Collateral Under Master Netting Arrangements
Amount of right to receive cash collateral, offset against derivative liability		$ 30

Investments in Debt and Equit67

Investments in Debt and Equity Securities (Available-For-Sale Investments) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	$ 1,986	$ 1,882
Gross Unrealized Holding Losses	87	83
Estimated Fair Value	6,398	6,214
Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,942	1,846
Gross Unrealized Holding Losses	83	76
Estimated Fair Value	5,992	5,817
Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	189	179
Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,869	1,823
Gross Unrealized Holding Losses	78	58
Estimated Fair Value	3,834	3,590
Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	22	7
Gross Unrealized Holding Losses	1	8
Estimated Fair Value	480	432
Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	12	5
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	307	185
Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	38	11
Gross Unrealized Holding Losses		5
Estimated Fair Value	1,038	1,254
Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	3	4
Estimated Fair Value	144	177
Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	44	36
Gross Unrealized Holding Losses	4	7
Estimated Fair Value	406	397
Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	27	29
Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	34	32
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	98	95
Other Classification [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2	1
Gross Unrealized Holding Losses	1	3
Estimated Fair Value	97	92
Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	6	3
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	80	74
Other Classification [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	47	45
Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	2
Estimated Fair Value	57	62
Duke Energy Carolinas [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,077	1,028
Gross Unrealized Holding Losses	49	40
Estimated Fair Value	3,166	3,041
Duke Energy Carolinas [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,077	1,028
Gross Unrealized Holding Losses	48	39
Estimated Fair Value	3,163	3,038
Duke Energy Carolinas [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	66	34
Duke Energy Carolinas [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,045	1,021
Gross Unrealized Holding Losses	44	27
Estimated Fair Value	2,128	2,094
Duke Energy Carolinas [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	13	3
Gross Unrealized Holding Losses	1	5
Estimated Fair Value	309	292
Duke Energy Carolinas [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2	1
Estimated Fair Value	42	33
Duke Energy Carolinas [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	16	3
Gross Unrealized Holding Losses		3
Estimated Fair Value	482	438
Duke Energy Carolinas [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	3	4
Estimated Fair Value	136	147
Duke Energy Carolinas [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	3	3
Duke Energy Carolinas [Member] | Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	3	3
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	869	821
Gross Unrealized Holding Losses	35	37
Estimated Fair Value	2,897	2,842
Progress Energy [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	865	818
Gross Unrealized Holding Losses	35	37
Estimated Fair Value	2,829	2,779
Progress Energy [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	123	145
Progress Energy [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	824	802
Gross Unrealized Holding Losses	34	31
Estimated Fair Value	1,706	1,496
Progress Energy [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	9	4
Gross Unrealized Holding Losses		3
Estimated Fair Value	171	140
Progress Energy [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	10	4
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	265	152
Progress Energy [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	22	8
Gross Unrealized Holding Losses		2
Estimated Fair Value	556	816
Progress Energy [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	8	30
Progress Energy [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	3
Estimated Fair Value	68	63
Progress Energy [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	21	18
Progress Energy [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	3
Estimated Fair Value	47	45
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	645	609
Gross Unrealized Holding Losses	29	30
Estimated Fair Value	2,107	2,039
Duke Energy Progress [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	645	609
Gross Unrealized Holding Losses	29	30
Estimated Fair Value	2,106	2,038
Duke Energy Progress [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	58	110
Duke Energy Progress [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	614	596
Gross Unrealized Holding Losses	28	25
Estimated Fair Value	1,379	1,178
Duke Energy Progress [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	7	3
Gross Unrealized Holding Losses		2
Estimated Fair Value	118	96
Duke Energy Progress [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	10	4
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	265	150
Duke Energy Progress [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	14	6
Gross Unrealized Holding Losses		2
Estimated Fair Value	281	486
Duke Energy Progress [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	5	18
Duke Energy Progress [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1	1
Duke Energy Progress [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1	1
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	224	212
Gross Unrealized Holding Losses	6	7
Estimated Fair Value	774	792
Duke Energy Florida [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	220	209
Gross Unrealized Holding Losses	6	7
Estimated Fair Value	723	741
Duke Energy Florida [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	65	35
Duke Energy Florida [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	210	206
Gross Unrealized Holding Losses	6	6
Estimated Fair Value	327	318
Duke Energy Florida [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2	1
Gross Unrealized Holding Losses		1
Estimated Fair Value	53	44
Duke Energy Florida [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value		2
Duke Energy Florida [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	8	2
Estimated Fair Value	275	330
Duke Energy Florida [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	3	12
Duke Energy Florida [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	3
Estimated Fair Value	51	51
Duke Energy Florida [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	4	6
Duke Energy Florida [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	3
Estimated Fair Value	47	45
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	29	27
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	104	101
Duke Energy Indiana [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	29	27
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	104	101
Duke Energy Indiana [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value		2
Duke Energy Indiana [Member] | Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	28	27
Estimated Fair Value	73	71
Duke Energy Indiana [Member] | Other Classification [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	2	2
Duke Energy Indiana [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	$ 29	$ 26

Investments in Debt and Equit68

Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Jun. 30, 2016USD ($)
Debt Instrument [Line Items]
Due in one year or less	$ 88
Due after one through five years	660
Due after five through 10 years	511
Due after 10 years	991
Total	2,250
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Due in one year or less	6
Due after one through five years	198
Due after five through 10 years	235
Due after 10 years	533
Total	972
Progress Energy [Member]
Debt Instrument [Line Items]
Due in one year or less	65
Due after one through five years	375
Due after five through 10 years	200
Due after 10 years	407
Total	1,047
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Due in one year or less	14
Due after one through five years	191
Due after five through 10 years	154
Due after 10 years	310
Total	669
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Due in one year or less	51
Due after one through five years	184
Due after five through 10 years	46
Due after 10 years	97
Total	378
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Due in one year or less	2
Due after one through five years	16
Due after five through 10 years	8
Due after 10 years	5
Total	$ 31

Investments in Debt and Equit69

Investments in Debt and Equity Securities (Realized Gains and Losses)(Details) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	$ 64	$ 28	$ 118	$ 130
Realized losses	42	17	92	31
Duke Energy Carolinas [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	33	17	67	107
Realized losses	19	11	56	23
Progress Energy [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	31	9	50	21
Realized losses	23	5	36	6
Duke Energy Progress [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	27	8	42	17
Realized losses	20	4	31	5
Duke Energy Florida [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	4	1	8	4
Realized losses	$ 3	$ 1	$ 5	$ 1

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 108	$ 26
Total assets	6,506	6,240
Derivative liabilities	(428)	(419)
Net assets	6,078	5,821
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2
Total assets	4,584	4,260
Derivative liabilities	(1)
Net assets	4,583	4,260
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	72	16
Total assets	1,717	1,793
Derivative liabilities	(427)	(419)
Net assets	1,290	1,374
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	34	10
Total assets	38	15
Net assets	38	15
Fair Value, Inputs, Not Categorized [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	167	172
Net assets	167	172
Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3,834	3,590
Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3,666	3,418
Equity Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1
Equity Securities [Member] | Ndtf [Member] | Fair Value, Inputs, Not Categorized [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	167	172
Equity Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	98	95
Equity Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	98	95
Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,158	2,227
Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	744	672
Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,414	1,555
Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	308	302
Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	74	75
Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	230	222
Debt Securities [Member] | Other Classification [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	4	5
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	18
Total assets	3,184	3,041
Derivative liabilities	(89)	(45)
Net assets	3,095	2,996
Duke Energy Carolinas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,205	2,168
Net assets	2,205	2,168
Duke Energy Carolinas [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	18
Total assets	809	698
Derivative liabilities	(89)	(45)
Net assets	720	653
Duke Energy Carolinas [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3	3
Net assets	3	3
Duke Energy Carolinas [Member] | Fair Value, Inputs, Not Categorized [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	167	172
Net assets	167	172
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,128	2,094
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,960	1,922
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member] | Fair Value, Inputs, Not Categorized [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	167	172
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,035	944
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	245	246
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	790	698
Duke Energy Carolinas [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3	3
Duke Energy Carolinas [Member] | Debt Securities [Member] | Other Classification [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3	3
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	54	11
Total assets	2,951	2,853
Derivative liabilities	(100)	(322)
Net assets	2,851	2,531
Progress Energy [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,226	1,940
Net assets	2,226	1,940
Progress Energy [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	54	11
Total assets	725	913
Derivative liabilities	(100)	(322)
Net assets	625	591
Progress Energy [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,706	1,496
Progress Energy [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,706	1,496
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,123	1,283
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	499	426
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	624	857
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	68	63
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	21	18
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	47	45
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	25	2
Total assets	2,132	2,041
Derivative liabilities	(18)	(98)
Net assets	2,114	1,943
Duke Energy Progress [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	1,608	1,320
Net assets	1,608	1,320
Duke Energy Progress [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	25	2
Total assets	524	721
Derivative liabilities	(18)	(98)
Net assets	506	623
Duke Energy Progress [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,379	1,178
Duke Energy Progress [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,379	1,178
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	727	860
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	228	141
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	499	719
Duke Energy Progress [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1	1
Duke Energy Progress [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1	1
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	29	7
Total assets	803	799
Derivative liabilities	(76)	(216)
Net assets	727	583
Duke Energy Florida [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	602	609
Net assets	602	609
Duke Energy Florida [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	29	7
Total assets	201	190
Derivative liabilities	(76)	(216)
Net assets	125	(26)
Duke Energy Florida [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	327	318
Duke Energy Florida [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	327	318
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	396	423
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	271	285
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	125	138
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	51	51
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	4	6
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	47	45
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	5	3
Derivative liabilities	(8)	(7)
Net assets	(3)	(4)
Duke Energy Ohio [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(8)	(7)
Net assets	(8)	(7)
Duke Energy Ohio [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	5	3
Net assets	5	3
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	31	7
Total assets	135
Derivative liabilities	1
Net assets	134	108
Duke Energy Indiana [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2
Total assets	75
Derivative liabilities	1
Net assets	74	73
Duke Energy Indiana [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	31
Net assets	31	28
Duke Energy Indiana [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	29	7
Total assets	29
Net assets	29	7
Duke Energy Indiana [Member] | Equity Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	73	71
Duke Energy Indiana [Member] | Equity Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	73	71
Duke Energy Indiana [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	31	30
Duke Energy Indiana [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		2
Duke Energy Indiana [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	$ 31	$ 28

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation of Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments
Beginning balance	$ 6		$ 15	$ 4
Total pretax gains (losses) included in earnings				18
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	34		34	24
Sales			(1)
Settlements	(6)		(13)	(22)
Total gains (losses) included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities	4		3	4
Ending balance	38	$ 28	38	28
Derivatives (net)
Beginning balance	2		10	(1)
Total pretax gains (losses) included in earnings				18
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases	34		34	24
Settlements	(6)		(13)	(22)
Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities	4		3	4
Ending balance	34	23	34	23
Investments [Member]
Investments
Beginning balance	4		5	5
Sales			(1)
Ending balance	4	5	4	5
Duke Energy Ohio [Member]
Derivatives (net)
Beginning balance		7	3	(18)
Total pretax gains (losses) included in earnings		(4)		21
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases	5		5
Sales		5		5
Settlements		(3)	(2)	(3)
Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities			(1)
Ending balance	5	5	5	5
Duke Energy Indiana [Member]
Derivatives (net)
Beginning balance	2	3	7	14
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases	29	18	29	18
Settlements	(6)	(10)	(11)	(19)
Total gains included on the Condensed Consolidated Balance Sheet as regulatory assets or liabilities	4	6	4	4
Ending balance	$ 29	$ 17	$ 29	$ 17

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure) (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016USD ($)$ / MWh	Dec. 31, 2015USD ($)$ / MWh	Mar. 31, 2016USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 34	$ 10	$ 2	$ 23		$ (1)
Financial Transmission Rights [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 34	$ 10
Financial Transmission Rights [Member] | Minimum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	(1.64)	(0.74)
Financial Transmission Rights [Member] | Maximum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	8.64	7.29
Duke Energy Ohio [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 5	$ 3		5	$ 7	(18)
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 5	$ 3
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Minimum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	0.36	0.67
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Maximum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	2.47	2.53
Duke Energy Indiana [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 29	$ 7	$ 2	$ 17	$ 3	$ 14
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability) | $	$ 29	$ 7
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Minimum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	(1.64)	(0.74)
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Maximum [Member] | RTO Auction Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Financial Transmission Rights | $ / MWh	8.64	7.29

Fair Value Measurements (Additi

Fair Value Measurements (Additional Fair Value Disclosure) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 42,273	$ 39,569
Long-term debt, fair value	47,953	42,537
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	9,360	8,367
Long-term debt, fair value	10,874	9,156
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	15,486	14,464
Long-term debt, fair value	16,715	15,856
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	6,565	6,518
Long-term debt, fair value	7,344	6,757
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	5,540	4,266
Long-term debt, fair value	5,226	4,908
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	1,887	1,598
Long-term debt, fair value	2,134	1,724
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,937	3,768
Long-term debt, fair value	$ 4,717	$ 4,219

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 3,394
Cinergy Receivables [Member]
Variable Interest Entities [Line Items]
Minimum equity balance required by Cinergy Receivables	3
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 325
Percent of proceeds received as cash	75.00%
Percent of proceeds received as subordinated note	25.00%
Duke American Transmission Company [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	50.00%
Atlantic Coast Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	40.00%
Sabal Trail Transmission Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	7.50%
OVEC [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	9.00%
Duke Energy Carolinas [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 1,000
Duke Energy Carolinas [Member] | DERF [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	425
Duke Energy Progress [Member] | DEPR [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	300
Duke Energy Florida [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	1,294
Duke Energy Florida [Member] | DEFR [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	225
Duke Energy Florida [Member] | DEFPF [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	1,294
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 250
Duke Energy Ohio [Member] | Cinergy Receivables [Member]
Variable Interest Entities [Line Items]
Fixed interest rate added to LIBOR to compute variable rate	1.00%
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 500
Duke Energy Indiana [Member] | Cinergy Receivables [Member]
Variable Interest Entities [Line Items]
Fixed interest rate added to LIBOR to compute variable rate	1.00%

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 676	$ 857	$ 960	$ 2,036
Restricted receivables of VIEs	1,943	1,748
Regulatory Assets, Current	825	877
Other current assets	451	327
Regulatory Assets, Noncurrent	11,290	11,373
Investments and other assets	2,972	3,042
Property, plant and equipment, cost	115,143	112,826
Accumulated depreciation and amortization	(38,412)	(37,665)
Other deferred debits	30	43
Accounts payable	2,221	2,400
Current maturities of long-term debt	2,342	2,074
Other current liabilities	1,784	2,115
Long-Term Debt	39,931	37,495
Deferred income taxes	13,038	12,705
Asset retirement obligation	10,231	10,264
Other liabilities	1,730	1,706
Duke Energy Carolinas [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	16	13	28	13
Restricted receivables of VIEs	696	596
Regulatory Assets, Current	262	305
Other current assets	86	128
Regulatory Assets, Noncurrent	2,856	2,766
Investments and other assets	916	999
Property, plant and equipment, cost	40,285	39,398
Accumulated depreciation and amortization	(13,880)	(13,521)
Other deferred debits	3	4
Accounts payable	565	753
Current maturities of long-term debt	468	356
Other current liabilities	400	519
Long-Term Debt	8,592	7,711
Deferred income taxes	6,472	6,146
Asset retirement obligation	3,910	3,918
Other liabilities	645	621
Duke Energy Progress [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	8	15	13	9
Restricted receivables of VIEs	421	349
Regulatory Assets, Current	187	264
Other current assets	35	121
Regulatory Assets, Noncurrent	2,744	2,710
Investments and other assets	509	486
Property, plant and equipment, cost	27,771	27,313
Accumulated depreciation and amortization	(10,350)	(10,141)
Other deferred debits	2	3
Accounts payable	300	399
Current maturities of long-term debt	252	2
Other current liabilities	314	412
Long-Term Debt	6,163	6,366
Deferred income taxes	3,167	3,027
Asset retirement obligation	4,594	4,567
Other liabilities	23	45
Duke Energy Florida [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	8	8	$ 13	$ 8
Restricted receivables of VIEs	355	308
Regulatory Assets, Current	135	98
Other current assets	43	21
Regulatory Assets, Noncurrent	2,553	2,725
Investments and other assets	288	292
Property, plant and equipment, cost	15,938	15,343
Accumulated depreciation and amortization	(4,730)	(4,720)
Other deferred debits	3	2
Accounts payable	390	322
Current maturities of long-term debt	48	13
Other current liabilities	361	452
Long-Term Debt	5,492	4,253
Deferred income taxes	2,571	2,460
Asset retirement obligation	792	802
Other liabilities	103	146
DEFPF [Member] | Duke Energy Florida [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets, Current	34
Other current assets	7
Regulatory Assets, Noncurrent	1,194
Current maturities of long-term debt	35
Long-Term Debt	1,243
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Long-Term Debt	425	425
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Long-Term Debt	300	254
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Long-Term Debt	225	225
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Long-Term Debt	325	325
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Other current assets	223	138
Property, plant and equipment, cost	2,578	2,015
Accumulated depreciation and amortization	(376)	(321)
Current maturities of long-term debt	154	108
Long-Term Debt	866	968
Deferred income taxes	31	289
Other liabilities	$ 277	$ 33

Variable Interest Entities (S76

Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 3,394
Long-Term Debt	39,931	$ 37,495
Duke Energy Carolinas [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	1,000
Long-Term Debt	8,592	7,711
Duke Energy Progress [Member]
Variable Interest Entities [Line Items]
Long-Term Debt	6,163	6,366
Duke Energy Florida [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	1,294
Long-Term Debt	$ 5,492	4,253
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date	Dec. 1, 2018
Debt Instrument, Face Amount	$ 325
Long-Term Debt	$ 325	325
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date	Dec. 1, 2018
Debt Instrument, Face Amount	$ 425
Long-Term Debt	$ 425	425
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date	Feb. 1, 2019
Debt Instrument, Face Amount	$ 300
Long-Term Debt	$ 300	254
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date	Apr. 1, 2019
Debt Instrument, Face Amount	$ 225
Long-Term Debt	$ 225	$ 225

Variable Interest Entities (S77

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 613	$ 499
Investments and other assets	2,972	3,042
Other current liabilities	1,784	2,115
Deferred credits and other liabilities	32,869	32,490
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies		0
Investments in equity method unconsolidated affiliates	474	387
Total assets	474	387
Other current liabilities	3	3
Deferred credits and other liabilities	13	14
Total liabilities	16	17
Net assets	458	370
Renewables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies		0
Investments in equity method unconsolidated affiliates	222	235
Total assets	222	235
Net assets	222	235
Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies		0
Investments in equity method unconsolidated affiliates	252	152
Total assets	252	152
Other current liabilities	3	3
Deferred credits and other liabilities	13	14
Total liabilities	16	17
Net assets	236	135
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	35	84
Investments and other assets	16	20
Other current liabilities	82	153
Deferred credits and other liabilities	2,054	1,998
Duke Energy Ohio [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	39	47
Total assets	39	47
Net assets	39	47
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	60	71
Other current liabilities	101	97
Deferred credits and other liabilities	3,280	3,219
Duke Energy Indiana [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	58	60
Total assets	58	60
Net assets	$ 58	$ 60

Variable Interest Entities (Fai

Variable Interest Entities (Fair Value Assumptions)(Details) - Cinergy Receivables [Member]	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.50%	0.60%
Discount rate	1.40%	1.20%
Receivable turnover rate	13.20%	12.90%
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.30%	0.30%
Discount rate	1.40%	1.20%
Receivable turnover rate	10.60%	10.60%

Variable Interest Entities (Rec

Variable Interest Entities (Receivables Sold)(Details) - Cinergy Receivables [Member] - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 208	$ 233
Less: Retained interests	39	47
Net receivables sold	169	186
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	279	260
Less: Retained interests	58	60
Net receivables sold	$ 221	$ 200

Variable Interest Entities (Sal

Variable Interest Entities (Sales and Cash Flows)(Details) - Cinergy Receivables [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 429	$ 425	$ 961	$ 1,069
Loss recognized on sale	2	2	5	5
Cash proceeds from receivables sold	427	467	964	1,107
Collection fees received	0	1	0	1
Return received on retained interests	0	1	1	2
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	623	637	1,258	1,353
Loss recognized on sale	2	2	5	5
Cash proceeds from receivables sold	612	660	1,255	1,382
Collection fees received	1	1	1	1
Return received on retained interests	$ 1	$ 1	$ 2	$ 3

Common Stock (Earnings Per Shar

Common Stock (Earnings Per Share Data)(Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Common Stock [Line Items]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ 510	$ 600	$ 1,201	$ 1,373
Average shares, basic	689	692	689	700
Average shares, diluted	690	692	689	700
EPS, basic (usd per share)	$ 0.74	$ 0.87	$ 1.74	$ 1.96
EPS, diluted (usd per share)	$ 0.74	$ 0.87	$ 1.74	$ 1.96
Common Class A [Member]
Common Stock [Line Items]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ 508	$ 600	$ 1,199	$ 1,372
Average shares, basic	689	692	689	700
Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements	1
Average shares, diluted	690	692	689	700
EPS, basic (usd per share)	$ 0.74	$ 0.87	$ 1.74	$ 1.96
EPS, diluted (usd per share)	$ 0.74	$ 0.87	$ 1.74	$ 1.96
Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation	2	2	2	2
Dividends declared per share (usd per share)	$ 0.825	$ 0.795	$ 1.65	$ 1.59

Common Stock Common Stock (Acce

Common Stock Common Stock (Accelerated Share Repurchase) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2015	Apr. 30, 2015	Jun. 30, 2015	Jun. 30, 2015	Apr. 06, 2015
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount		$ 1,500
Payments for Repurchase of Common Stock		$ 1,500		$ 1,500
Delivered Shares from Dealers	3.2	16.6	19.8
Fair Market Value of Delivered Shares	$ 225	$ 1,275
Percentage of ASR common stock received					85.00%
Accelerated Share Repurchases, Final Price Paid Per Share			$ 75.75
Goldman Sachs [Member]
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock		750
JPMorgan Chase [Member]
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock		$ 750

Common Stock Common Stock (Equi

Common Stock Common Stock (Equity Securities Offering) (Details) - Piedmont Natural Gas [Member] shares in Millions	Jun. 30, 2016$ / sharesshares
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered	10.6
Then Forward Price | $ / shares	$ 69.84
Shares required to net settle	2.1

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	$ 15	$ 19	$ 27	$ 33
Tax benefit associated with stock-based compensation expense	5	7	9	12
Stock-based compensation costs capitalized	1	1	2	2
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	10	11	17	20
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	$ 5	$ 8	$ 10	$ 13

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details)	6 Months Ended
	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Matching contribution percentage	100.00%
Eligible pay percentage	6.00%
Additional savings plan account contribution percentage for employees not participating in defined pension plans	4.00%
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Maximum years of participation	35 years

Employee Benefit Plans Employee

Employee Benefit Plans Employee Benefit Plans (Plan Contributions) (Details) - Pension Plan [Member] $ in Millions	6 Months Ended
	Jun. 30, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	$ 132
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	42
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	42
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	21
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	21
Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	1
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions by Employer	$ 9

Employee Benefit Plans (Compone

Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Qualified Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 37	$ 39	$ 73	$ 79
Interest cost on projected benefit obligation	83	81	166	163
Expected return on plan assets	(129)	(129)	(258)	(258)
Amortization of actuarial loss (gain)	33	44	66	87
Amortization of prior service cost (credit)	(4)	(3)	(8)	(7)
Other	1	2	4	4
Net periodic costs	21	34	43	68
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	12	12	24	25
Interest cost on projected benefit obligation	22	20	43	41
Expected return on plan assets	(36)	(33)	(71)	(69)
Amortization of actuarial loss (gain)	8	10	16	20
Amortization of prior service cost (credit)	(2)	(2)	(4)	(4)
Other			1	1
Net periodic costs	4	7	9	14
Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	10	11	21	22
Interest cost on projected benefit obligation	27	26	53	52
Expected return on plan assets	(42)	(41)	(84)	(84)
Amortization of actuarial loss (gain)	13	17	27	34
Amortization of prior service cost (credit)	(1)	(1)	(2)	(2)
Other			1	1
Net periodic costs	7	12	16	23
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	6	6	12	12
Interest cost on projected benefit obligation	13	12	25	24
Expected return on plan assets	(20)	(21)	(41)	(41)
Amortization of actuarial loss (gain)	5	9	11	17
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Other	1	1	1	1
Net periodic costs	4	6	7	12
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	5	5	10	10
Interest cost on projected benefit obligation	14	13	28	27
Expected return on plan assets	(21)	(22)	(42)	(44)
Amortization of actuarial loss (gain)	7	8	14	16
Amortization of prior service cost (credit)		(1)		(1)
Other		1		1
Net periodic costs	5	4	10	9
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	2	2
Interest cost on projected benefit obligation	5	4	10	9
Expected return on plan assets	(7)	(7)	(14)	(13)
Amortization of actuarial loss (gain)	1	3	2	5
Net periodic costs		1		3
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	2	2	4	5
Interest cost on projected benefit obligation	7	7	14	14
Expected return on plan assets	(11)	(11)	(21)	(21)
Amortization of actuarial loss (gain)	3	4	6	7
Net periodic costs	1	2	3	5
Non-Qualified Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	1	1
Interest cost on projected benefit obligation	3	3	7	7
Amortization of actuarial loss (gain)	2	1	4	3
Net periodic costs	6	5	12	11
Non-Qualified Pension Plan [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1		1	1
Net periodic costs	1		1	1
Non-Qualified Pension Plan [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost				1
Interest cost on projected benefit obligation	1	1	2	2
Amortization of actuarial loss (gain)		1	1	1
Net periodic costs	1	2	3	4
Non-Qualified Pension Plan [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	1	1	1
Net periodic costs	1	1	1	1
Non-Qualified Pension Plan [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	1	1	1
Amortization of actuarial loss (gain)				1
Net periodic costs	1	1	1	2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	2	3
Interest cost on projected benefit obligation	9	9	17	18
Expected return on plan assets	(4)	(3)	(7)	(6)
Amortization of actuarial loss (gain)	2	7	3	13
Amortization of prior service cost (credit)	(36)	(35)	(71)	(70)
Net periodic costs	(28)	(21)	(56)	(42)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost		1		1
Interest cost on projected benefit obligation	2	2	4	4
Expected return on plan assets	(2)	(2)	(4)	(4)
Amortization of actuarial loss (gain)	(1)	(1)	(2)	(1)
Amortization of prior service cost (credit)	(3)	(3)	(6)	(7)
Net periodic costs	(4)	(3)	(8)	(7)
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost		1		1
Interest cost on projected benefit obligation	3	3	7	7
Amortization of actuarial loss (gain)	6	7	11	14
Amortization of prior service cost (credit)	(25)	(25)	(51)	(51)
Net periodic costs	(16)	(14)	(33)	(29)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	2	2	4	4
Amortization of actuarial loss (gain)	3	4	6	9
Amortization of prior service cost (credit)	(17)	(16)	(34)	(33)
Net periodic costs	(12)	(10)	(24)	(20)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	1	3	3
Amortization of actuarial loss (gain)	3	2	5	5
Amortization of prior service cost (credit)	(9)	(7)	(18)	(16)
Net periodic costs	(5)	(4)	(10)	(8)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	1	1	1
Amortization of actuarial loss (gain)	(1)		(1)
Net periodic costs		1		1
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	2	2	2
Expected return on plan assets	$ (1)		(1)
Amortization of actuarial loss (gain)		(1)	$ (1)	(1)
Net periodic costs		$ 1		$ 1

Employee Benefit Plans (Employe

Employee Benefit Plans (Employee Savings Plans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Employee Savings Plans [Abstract]
Employer contributions	$ 39	$ 37	$ 91	$ 86
Duke Energy Carolinas [Member]
Employee Savings Plans [Abstract]
Employer contributions	13	13	31	29
Progress Energy [Member]
Employee Savings Plans [Abstract]
Employer contributions	12	12	27	26
Duke Energy Progress [Member]
Employee Savings Plans [Abstract]
Employer contributions	8	8	19	19
Duke Energy Florida [Member]
Employee Savings Plans [Abstract]
Employer contributions	4	3	8	7
Duke Energy Ohio [Member]
Employee Savings Plans [Abstract]
Employer contributions	1	1	2	2
Duke Energy Indiana [Member]
Employee Savings Plans [Abstract]
Employer contributions	$ 2	$ 2	$ 4	$ 4

Income Taxes Income Taxes (Taxe

Income Taxes Income Taxes (Taxes on Foreign Earnings) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Unremitted Earnings [Member] | International Energy [Member]
Income Tax Disclosure [Line Items]
U.S. Income Taxes on Foreign Earnings	$ 4	$ 16
Previously Remitted Earnings [Member]
Income Tax Disclosure [Line Items]
U.S. Income Taxes on Foreign Earnings		$ (95)

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rates) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	31.80%	35.60%	27.20%	33.60%
Duke Energy Carolinas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	35.10%	36.60%	34.60%	36.20%
Progress Energy [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	36.00%	39.20%	36.30%	37.10%
Duke Energy Progress [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	35.50%	40.60%	35.40%	36.00%
Duke Energy Florida [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	37.60%	38.70%	37.70%	38.60%
Duke Energy Ohio [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	34.30%	35.00%	29.20%	36.80%
Duke Energy Indiana [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	36.10%	36.40%	33.10%	36.50%